Costco, like Sam's Club, is membership only, and their membership is $45 per year. They are not as conveniently located for me as Sam's, so even though I like the products a little bit better, we've stuck with Sam's and let our membership to Costco go by the wayside! I really like Kirkland (Costco house brand) products, though. I especially recommend the Kirkland pet food--it is excellent for the value. They also offer coupons, something Sam's does not do. You can really get some great deals on items already priced wholesale. They also have a gas pump with lower prices, and good prices on tires.