Business Insider/Jessica Tyler A Sam's Club store in Westchester County, New York.

Costco and Sam's Club are similar membership-based warehouse stores that offer a wide variety of products and services, from eye exams to photo printing.

The only significant difference between the stores is the cost of membership, with Sam's Club costing $15 less annually than Costco.

I went to a Costco and Sam's Club in New York and found that the cost and quality were comparable enough that the deciding factor between the two stores might just be how close you live to each one.

Costco and Sam's Club are membership-based warehouse stores selling groceries, clothing, furniture, and, well, lots of other stuff. Both stores offer eye and ear exams, a pharmacy, one-hour photo services, and a food court at affordable prices. Even the return policies are similar, with both stores accepting most items with or without a receipt.

After visiting both stores in succession, I found there was really only one major difference between them: the cost of membership. Costco charges $60 annually for a basic membership and $120 for an executive membership, while Sam's Club charges $45 annually for a basic membership and $100 for a premium membership.

According to a grocery-store ranking from Consumer Reports, the higher membership costs at Costco might be worth it - it ranked higher than Sam's Club in cleanliness, meat and produce quality, customer service, store-brand quality, and prices of organic items.

To see for myself which store offers a better deal, I went to Costco and Sam's Club stores in Westchester County, New York. This is what I found: