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14 Costly Mistakes Every Costco Shopper Makes at Least Once

Certain choices could be costing you time and money.

There's no place quite like Costco. Taking a trip to the big-box store means access to endless possibilities—discounted lawn chairs, entertainment systems, a 28-pound bucket of mac and cheese, you name it.

While there's no "right" way to shop at the club, there are many, many "wrong" ways. These questionable decisions could be costing you additional time, money, and energy.

To help you make the most of your membership, we rounded up some common shopping mistakes that you'll want to avoid the next time you visit the warehouse chain.

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Shopping without a list

costco cart
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One of Costco's many selling points is its vast selection of products. However, with so many options to choose from, it can be easy to stray from what you intended on purchasing prior to stepping foot into the store. Sticking to a pre-determined list can help you avoid those tempting impulse buys, ultimately alleviating the strain on your wallet.

Shopping on an empty stomach


As the popular Snickers slogan put it, "You're not you when you're hungry." This sentiment can also present itself when you shop. While you've probably been told not to buy groceries while hungry because you may end up buying more food than you planned, this purchasing behavior isn't limited to food.

In a 2015 study, researchers found that hungry shoppers spent 64% more money and bought more non-food items than less hungry customers. So, be sure to eat up before heading over to Costco!

Shopping when it's busy

costco checkout lanes
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Although there isn't a "perfect" time to shop at Costco, there are some days and hours that are typically more overwhelming. According to Finance Buzz, weekends and Mondays are some of the busiest days of the week to swing by the warehouse club. Lunchtime and weeknights can also get hectic with people stopping by during their lunch break or after work.

If your schedule allows for it, shopping at Costco when the store opens or closes could be most optimal. Or, if you prefer to shop in the afternoon, Apartment Therapy notes that Tuesday through Thursday tend to be calmer days, particularly after lunch and before people finish their work days.

Buying the wrong items in bulk

Costco Bakery cookies and cakes

While a 24-count package of chocolate chunk cookies from Costco's bakery might seem like a much-needed purchase in the moment, you might not be able to eat all of them before they become stale. Prior to buying something in bulk, assess whether you'll be able to finish the item before it goes bad, and then proceed from there.

Stocking up on produce

boxes of costco produce
Mihai Andritoiu / Shutterstock

Aside from bulk produce having a higher likelihood of spoiling before you're able to finish it, multiple Costco shoppers have reported complaints about the retailer's fruits and vegetables going bad quickly.

In a Reddit thread dedicated to Costco products that customers no longer buy, one user wrote, "All the produce. It rots way faster than my local produce place." Another one added, "The produce has really gone downhill unfortunately. It's almost to the point of skipping the entire section."

Steering clear of bulk items entirely

shopping in costco

If you're shopping for a single-person household, it might not seem necessary to purchase items in bulk. However, there are some items that you're always going to need: paper towels, toilet paper, dish soap, and the like. And if there are foods you regularly eat, it might actually make a lot of sense to stock up on them. Don't count yourself out of potential bulk-savings just because you're shopping for one.

Only buying name-brand products

starbucks brand coffee blend at costco
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Costco is home to many national and regional brands, but you're not going to want to overlook the store's lower-cost private-label brand. According to Costco's website, Kirkland Signature products are "designed to be of equal or better quality than national brands." Plus, many of the Costco-branded items are actually produced by big-name brands, according to the Motley Fool. They're just packaged under the Kirkland label. (We're looking at you, Starbucks).

Only buying Kirkland Signature products


That being said, not all Costco products are value deals. To ensure you're getting the best bang for your buck, you'll want to compare the price, size, and quality of the Kirkland Signature item to its brand-name equivalent.

Misinterpreting price tags

cases of vanilla extract at costco
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When shopping at Costo, understanding the retailer's pricing system is key. Prices that end in .99 or .98 denote that the product is regularly priced. According to Uproxx, "That means Costco didn't get a special deal from the supplier. It also means that the product is probably the same price as any other store (unless you're buying in bulk)."

Meanwhile, prices that end in .89, .79, .69, .59, .49, .39, .29, .19, or .09, signify that the item is a manufacturer's deal and can be sold at a cheaper price than other retailers. Products ending in .97 are manager-designated discounts aimed at opening up more shelf space for newer merchandise. Additionally, prices ending in .00 or .88 represent marked-down items that have been returned, are damaged, or have a low supply.

For confirmation of a product's impending discontinuation, be on the lookout for an asterisk in the top right corner of the price tag sign, which has been playfully dubbed the "Costco death star."

Not taking advantage of member perks

costco travel logo / Shutterstock

Having a Costco card unlocks countless opportunities. From discounted travel and car rental services to home and auto insurance deals, the retailer grants its members a variety of money-saving perks beyond its famous bulk offerings.

Overlooking the health services

Costco pharmacy
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Among Costco's many member perks is access to several different health services. In addition to selling discounted health insurance, Costco has a free membership prescription program that offers prescriptions at discounted prices.

Skipping over the gift cards

costco gift cards
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While gift cards might not seem like something you'd buy from a bulk retailer, it's something worth considering. On Reddit, users delighted over Costco's gift card deals on restaurants and activities. "We have popular, good local restaurant $100 gift cards at Costco for $75! Who wouldn't want 25% off their meal?" one Redditor commented. "The best thing is AMC 4 pack yellow tickets. $11.99 FOR FOUR!!!! Averages out to $3 per ticket!," another wrote.

Not downloading the Costco app

costco mobile app
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If you left your Costco card at home, have no fear. You can use Costco's mobile app to prove you belong. The app stores all your membership information, which can really come in handy if you get stopped by warehouse security. You can also use the app to pay at the register, view your receipts, gain access to current promotions, along with several other features.

Forgetting to fuel up

costco gas station
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Costco is celebrated for its low-priced gas, which can be up to 30 cents cheaper per gallon than a regular fill-up station, according to the Motley Fool. The lower price doesn't mean lower quality, either. The idea behind keeping prices low is to drive customers to the store.

"When there are inflationary pressures and prices are going up, people look to save on gas," Richard Galanti, Costco's chief financial officer, told CNN back in 2021. "For every 100 people who come to Costco to fill up on gas, more than half go shop inside afterwards."

Brianna Ruback
Brianna is a staff writer at Eat This, Not That! She attended Ithaca College, where she graduated with a degree in Journalism and a minor in Communication Studies. Read more about Brianna