Once people start shopping at Costco, their entire way of buying food and supplies seems to change. While there are plenty of deals and exceptional offers available, it’s important to know some of the common mistakes people make at Costco to guarantee that you’re getting your money’s worth. Just because the warehouse flaunts discounted prices and goods packaged in large volumes, that doesn’t mean it’s always the best deal around.

Perhaps you’re missing out with your membership level, or failing to notice all of the additional discounts available. You might find yourself overbuying simply because a price offers a good value, when in reality you can’t properly store all that food or get through the stocks of supplies. And let’s not get started on showing up at Costco without a clear idea of what you need.

We’ve assembled a list of some of the most common mistakes people make when shopping at Costco to ensure that you avoid wasting money. With these insider tips and tricks, you’ll be able to avoid pricy pitfalls and have a successful shopping trip.

One of the fundamentals of shopping at Costco is that it requires a membership. The two options for a personal membership are Gold Star and Executive, and each level comes with different features. In September of 2024, an increase in Costco membership fees took effect, and now the Gold Star membership costs $65 a year and the Executive level costs double that at $130. The former level is the most basic, and you might think it’s sufficient for your needs. However, once you start to look at what the Executive level has to offer, it’s often a better choice.

Both memberships provide two cards, so that you and someone else in your household can shop online and at all Costco warehouse locations worldwide. However, the Executive membership also offers a 2% annual reward on most sales (some exclusions apply, including purchases of gas or tobacco), as well as additional discounts and benefits on services, such as insurance and travel offers.

When you break it down, you would need to spend $3,250 per year for the upgraded membership price to be refunded with the cash-back rewards, which comes out to just over $270 per month. If you’re regularly stocking up on a large amount of food and household supplies, you’ll quickly reach that number within the year — not to mention the savings you’ll enjoy on services with Executive membership. 

It’s no secret that if you go to the grocery store hungry or without a plan, you’ll end up buying all sorts of junk you don’t really need. This is true at any ordinary supermarket, but the issue quickly amplifies at Costco. The layout of the store showcases aisle upon aisle of mass quantities of countless products that are both familiar and unfamiliar, and this can be overwhelming to say the least.

If you’re the kind of shopper who likes to casually browse and pick up items as they pique your interest, you might find yourself spending hundreds of dollars more at Costco. Instead of picking up an extra package of tomato sauce or a wedge of cheese, you’ll take home a carton with a dozen cans or a couple of pounds of cheddar. This is certainly useful if you regularly use these products, but less so if you’re shopping on a whim. To avoid the pitfalls of overdoing it (and a hefty bill), plan your shopping list to make your trip more efficient, and have a budget in mind before setting foot into the warehouse.

If you want to maximize your potential savings at Costco, you’ll want to do a little bit more digging, rather than simply roaming the aisles. Online, the company provides additional offers that can be especially worthwhile. Some deals are exclusive to either warehouse or online purchases, whereas others can be used no matter how you shop.

Costco offers online coupons on a monthly basis, which includes exceptional limited-time offers for the duration of their validity. Meanwhile, Hot Buys are available from a couple of days to a week, and these feature items are offered at a heavily discounted price. Some coupons are exclusive to Executive membership holders and can be found online.

To avoid having to chase after all of these discounts, just sign up to receive alerts regarding new offers as they come up. If you’re especially keen, join groups on platforms like Facebook or Reddit to exchange tips on the best deals. 

Having yet another app on your phone might feel like overkill, but if you want to be in the know, the Costco app is definitely a straightforward option. Just download it from the app store on your phone and sign in with your membership number for a personalized experience. Details about your account like your rewards balance and past orders are all located on the app, as well as a digital membership card. All the Costco deals and specials are also listed by category, including warehouse and online savings, “while supplies last” offers, and “treasure hunt” items. Instead of promptly forgetting about the sales you saw, you can mark the ones that interest you so you’re all set for your shopping trip.

Everyone has their own technique for making shopping lists, but with Costco’s app it’s totally streamlined. Choose the items to include and have the app ready to go once you step foot inside the warehouse. Meanwhile, if you don’t live close to a Costco location, gas prices are also monitored on the app, allowing you to keep track of fluctuations so that you always make the trip to fill up when the cost is lowest. Although the Costco app isn’t exactly technologically advanced, it still offers plenty of neat tricks that make your shopping experience that much smoother.

One of the main draws of Costco is the value of buying items in high volumes. However, this can backfire if you end up purchasing far more than you need just because it seems like a good deal. Although you might think the smarter financial decision is to buy 24 cans of tomato sauce for a fraction of the price per unit, if you have nowhere to store them and end up stacking cans under your dining table, this is not ideal.

Meanwhile, non-shelf-stable items like produce, meat, dairy, and bread products pose even more of an issue, as these foods can quickly deteriorate. To reduce Costco bulk-food waste, it’s important to plan your shopping based on your needs, while considering what you can properly store in your home. Buying meat in bulk isn’t a bad idea if you’re separating large packages into portions and freezing them for several future dinners — but it won’t be worth it if you leave all that meat in the fridge and throw most of it out a week later.

Overdoing it at Costco can be detrimental for your bank account. People typically shop at Costco because of the good deals, but if they’re purchasing more than they need, the initial savings can become long-term losses. Keep your spending in check by making a shopping list and sticking to it. Limit your visits to the warehouse and use other smart-spending tips — like paying with a set amount of cash — to avoid going beyond your planned budget. 

Finding time to go shopping can be difficult when you have a busy schedule, but if you’re planning a monthly Costco trip, you’ll want to choose the timing wisely to optimize the experience. From the selection of samples to the crowds in the parking lot, there are several reasons to go at specific times. The most obvious time to avoid shopping at Costco is on weekends, when people with weekday jobs are shopping there before starting a new workweek.

Of course, if you also work weekdays, then it’ll be hard to avoid the weekend bargain-hunting hordes. The best time to shop at Costco for uncrowded aisles is between 1 p.m. and 4 p.m. from Tuesday through Thursday, so unless you have time for bulk shopping during a lunch break, your next best bet will be going right before closing time and keeping your visit quick.

Another reason to avoid weekend Costco visits is that you’ll be fighting with crowds of people over samples. Unfortunately, if you’re shopping on weekday evenings with the aim of avoiding crowds, chances are that you’ll also end up with fewer samples, as they won’t be offered in plentitude at those times. Keep in mind that if you’re shopping on the first day of coupon sales and other special offers, you’re likely to be among many other shoppers all trying to snag the latest deals, no matter what day of the week it is. 

Costco provides great value for products packaged in high volumes — but it doesn’t always offer the best deals in town. For items you buy regularly, you’ll want to do a bit of research to see if you’re actually getting the best price at Costco. You don’t have to do all the calculations yourself; online spreadsheets list common grocery and household products to compare the prices at Costco versus other popular stores. 

The consensus is that some items are better purchased at your local supermarket when they’re on sale — or even at their regular price. For example, soda and canned goods are commonly offered for deeper discounts at supermarkets. And while it will depend on your location and the other stores in your area, you might be better off getting many produce items from your local grocer.

If you’re buying generic brands at the supermarket, they could actually be cheaper than what’s offered at Costco. That said, for products of name-brand caliber, Costco is generally the more affordable option. At the warehouse, Costco’s Kirkland Signature brand generally provides high quality for a low price. Although buying in bulk is a good option for products and foods that you consume regularly, keep in mind that it may not be such a great deal when buying items that you rarely use. 

Costco offers price adjustments when items that you recently bought subsequently go on sale. Simply go to the return counter at the Costco location where you made the purchase. There’s no need to bring your receipt, since the customer-service employee will be able to access all your previous orders once you hand over your membership card.

A few rules are worth noting to ensure a smooth process. Price adjustment is only valid for items purchased within 30 days before a promotion begins. Additionally, not all items are eligible for this policy, and Costco reserves the right to deny price adjustments anytime.

Keep in mind that discrepancies between prices on the Costco website and at a warehouse location are also not eligible for an adjustment. For online purchases, there’s a form to fill out on the Costco website to process the refund. Additionally, Costco price matches its own merchandise, but it does not offer adjustments for items sold by other stores.

Although you might be used to shopping for products from the same brands over and over again, you won’t necessarily be able to find all of your favorites or get the best deals on them at Costco. One of the reasons the prices are low there is that the warehouses don’t stock a huge variety of brands. If you are open to trying new brands, then you have more of a chance of saving on the items that you regularly shop for.

Part of the fun of shopping at Costco is discovering new products you’ve never tried before. In fact, plenty of social media platforms are dedicated to the pursuit of sharing product discoveries amongst customers. Aside from various brands that the warehouse carries, the house brand, Kirkland Signature, is beloved by many shoppers. Behind the Kirkland logo there are plenty of successful companies offering their brand-name quality under Costco’s proprietary label. Numerous customers rave about the best Kirkland Signature products to buy, and chances are that once you start trying them at Costco, you’ll realize why they’re so popular. 

If you aren’t taking advantage of special deals on gift cards at Costco, you’re missing out. The warehouse offers excellent discounts on a wide variety of gift cards, but of course, they’re mostly sold in bulk. To receive the deal, you’ll need to buy multiple gift cards for a particular business or experience.

Gift cards for restaurants, cinemas, sports events, and concerts are some of the options on hand. If you’re always ordering from chain restaurants like Peet’s Coffee or Papa John’s, pick up a bulk purchase of $100 in gift cards for just under $80, and you’ll save 20% in the long run. You’ll also find gift cards for travel experiences and video game downloads. 

It’s worth noting that there are limits as to how many gift cards you can buy, with some of the offers having a maximum purchase of two per membership. Meanwhile, one hack for people who don’t yet have a Costco membership is to ask a member to purchase a Costco shop gift card for them, which can be used by non-members online or in a store. If you’re on the fence about getting your own membership, this is a great way to see what the shopping experience is like before committing. 

Costco has a very generous return policy, and one you’ll want to be familiar with if you’re a regular customer. The company’s risk-free 100% satisfaction guarantee is just one more way that Costco simplifies the shopping process for members, who most likely don’t even need to bring a receipt to make the return, since all purchases are recorded under their membership number.

On the one hand, the warehouse is very flexible about returns, making it extremely easy to bring back products you weren’t satisfied with or realized you didn’t actually want or need. If you’re on the fence about an item, simply get it with the rest of your shopping haul and give it a try, if you don’t mind possibly making a return trip if you’re less than overjoyed about it.

However, it’s important to note that although many returns can be made at any time following the purchase, some items must be returned within 90 days for a refund. Considering these include big-ticket items like electronics and appliances, you’ll want to be clear about what’s accepted at the return desk and within what time frame.

If you really want to make your Costco shopping trip even better, you’ll want to pay attention to price tags — and not just the digits left of the decimal point. As it turns out, the two numbers on the right, along with a special symbol, divulge information that may be worth your time. Whether it’s financial influencers or Costco employees spilling the beans, the secrets about Costco prices are becoming increasingly divulged, providing consumers with even more chances to shop smart and save.

For starters, the default price tag ends in “.99,” which indicates that the item is priced at regular cost. Clearance items end with “.97,” but aren’t otherwise marked as being on sale. The tag will indicate the date the price was reduced, and this doesn’t necessarily only happen once. Look out for prices ending in “.00,” which denotes a manager’s special; these will be some of the lowest markdowns you’ll find, and they often include the last few units of a product, or sometimes a floor model. Depending on the item, you’ll want to make sure it’s in good condition.

Price tags ending with nines, from “.49,” to “.89,” are a bit less straightforward, and suggest the product may or may not be on sale. These could include items that are being tested for popularity at that particular store. However, if your favorite Costco buy suddenly has an asterisk on the tag, grab as many as you can, because it will no longer be restocked.