4 Costco Mistakes You Need to Stop Making ASAP

Joining Costco can be a solid personal finance decision. The money you save by shopping there could more than make up for the cost of your membership fee (currently $60 for a basic membership and $120 for an Executive membership). 

But if you're going to pay for Costco, it's important to make the most of your membership. And that means avoiding these big mistakes that you might be making already.

1. Only buying brand names

Costco carries a variety of brands in stores and online. But if you're automatically skipping over the Kirkland version of whatever it is you're buying, you could be making a huge mistake.

Kirkland is Costco's signature brand. But don't assume it's inferior to the brands you know. Costco prides itself on quality and has a friendly return policy because it stands behind its products. It's no surprise that the store's signature brand offers a great amount of value.

2. Assuming an Executive membership isn't worth it

An Executive membership at Costco costs $120 a year, versus $60 for a basic membership. You may not be so inclined to pay the upgrade fee since the cheaper membership still gets you into the store. But one thing you should know is that you get 2% cash back on your Costco purchases with an Executive membership, which means that once you've spent beyond $3,000 in a single year, the upgrade becomes worth it.

Let's imagine you go to Costco every other week and buy $150 worth of groceries and household supplies. That's $3,900 in spending right there. And even if you don't shop at Costco that frequently, a single large purchase -- like a new TV or vacation package -- might easily put you over that threshold.

3. Not splitting bulk items with neighbors

One thing you may want to steer clear of at Costco is buying bulk items that are very perishable in nature. If you spend $10 on fruit but only manage to consume half of it before it spoils, you've thrown $5 away. 

But before you assume that you shouldn't buy perishables in bulk, see if neighbors or local friends of yours want to split certain items you use regularly. That way, you can benefit from Costco's bulk prices without risking food waste.

4. Limiting yourself to what's available at your local store

Costco's inventory can vary from one store to the next. And sometimes, certain products can go missing for weeks on end. 

But don't assume you're out of luck when that happens. If a given item you use regularly isn't available at your local store, check out Costco.com to see if you can buy it there. 

Costco usually charges a bit more for online purchases than in-store purchases because it commonly builds the cost of shipping into its prices with the former. But you might still find that Costco's online price is still cheaper than your local grocery store price. 

For example, right now, at Costco.com, you might pay $15.59 for a 62-ounce jar of peanut M&Ms, or $0.25 per ounce. The in-store price is probably less than $15.59. But if you eat peanut M&Ms every day and your local Costco is out, don't assume you should run to your regular store. Instead, consider ordering your M&Ms through Costco.com. At your local supermarket, you might pay $0.45 an ounce for a larger-sized bag.

A Costco membership has the potential to offer a world of value. Try to stop making these mistakes so you can benefit as much as possible from yours.