I don't shop at Costco or any of those places. My friends make fun of me, but I absolutely hate the whole concept.
Many years ago, (I was pg with my son who is turning 28), we joined Price Club, which I think turned into BJ's or one of those places. We ended up buying tons of stuff we didn't need, like giant bags of pistachio nuts. I think I went there 3 times, as DH was the one enamored of the idea.
I buy everything online, except groceries. I enjoy going to my local grocery store, which is fairly small and has almost everything I need. I do the rest at Trader Joe's and small local farms. We use our Amex for everything. In fact, I used Amex points to buy my family room furniture from Crate and Barrel when we moved into this house.