I shop at Walmart and Costco. The customers at the Costco appear much better off, but they seem much more arrogant and inconsiderate. They leave carts in the middle of the aisle, talk on phones with their families blocking the way, and so forth. Same behavior in the parking lots. Maybe it's because Costco is always packed. The shoppers at the Walmart definitely look less well off. They are much more respectful and considerate of others. I like shopping at the Walmart more.

The shoppers at costco vary drastically by location. If you have more than one warehouse reasonably close by, it may be worth your while to try them all.