I've shopped at Costco for nearly a decade. Here are the 8 biggest mistakes I see customers make.

Costco offers different levels of membership, but if you're a frequent shopper who buys most of your household goods at the chain, it may make sense to upgrade to the executive tier.

The executive membership costs $130 a year — an additional $65 from the base option — but it offers an annual 2% reward on qualifying purchases, up to $1,250.

Costco's Kirkland Signature line offers high-quality products for relatively cheap, often through relationships with large brands.

For example, the Kirkland Signature house-blend coffee is roasted by Starbucks (as indicated on the package) but often sold for several dollars less than the name-brand beans. Other products, like Kirkland's batteries, are also reportedly made by a major brand.

To ensure you're getting the best quality, do your research before you opt for the bargain brand.

At the wholesale chain, the restaurant gift cards typically cost less than their value, so you can get more food than you're paying for.

For instance, a two-pack of California Pizza Kitchen gift cards contains $100 worth of restaurant credit but costs $80, leading to about $20 in savings.

Costco's price tags aren't meaningless.

If the price of an item ends in $0.99, then it's being sold at the regular cost. But tags with $0.97 indicate the product is discounted or on clearance.

Price tags ending in $0.00 or $0.88 signal a "manager markdown," which means the product may have been a floor model or return, among other reasons. Closely inspect the item before purchasing it to make sure it's not damaged or missing any parts.

An asterisk next to the price — often referred to as "the death star" by Costco regulars — indicates this item will not be restocked, so you may want to buy more than one.

If an item goes on sale within 30 days of your purchase from Costco, you can request a refund for the price difference.

Although it can be difficult to keep tabs on every product you buy, this may be especially helpful for high-cost items.

However, you can't use this policy to compare the price of online orders to in-store warehouse offers.

Costco's bakery offers some great deals — you can find a dozen muffins or bagels for relatively cheap. But it can be difficult to eat them all before they get stale.

To avoid food waste, individually package each item in plastic wrap as soon as you get home. You can leave some out on the counter to enjoy over the next few days and store the rest in the freezer.

When you want to eat one, simply thaw the frozen muffin, bagel, or croissant in the microwave for 20 seconds, then toast it in the oven or air fryer at 325 degrees Fahrenheit for about five minutes to let the outside get nice and crispy.

You can also take it out of the freezer the night before and leave it on the counter to enjoy in the morning.

Even though you can find a pack of precut steaks in the meat section, it's usually cheaper to buy the whole roast.

For example, precut New York steak is priced at $15 per pound, but the whole roast costs $12 per pound.

Though having your steaks already cut is convenient, you can easily purchase the whole slab and slice it at home. This tip is especially helpful to save money when feeding a crowd.

If you walk into just about any Costco on a Saturday or Sunday, you're almost sure to find crowds and long lines. You may even have to circle the lot just to snag a parking spot.

This increased foot traffic can also lead to certain items going out of stock and longer waits at the food court.

To avoid this, it's best to go on a weekday. But if you must shop on the weekend, I recommend arriving 30 minutes before opening — there might already be a small line outside the entrance.

This story was originally published in November 2022, and most recently updated on September 13, 2024.