Costco Advantages
Best possible price 90%+ of the time
Costco Disadvantages
There aren’t as many around as I’d like, so you may have to drive
Very, very busy on weekends, and almost always have heavy traffic
Usually only 1-2 product choices within a given sub-category but they are usually the best, and highest quality options anyway
Sam’s Club Advantages:
More of them around
Much better diversity of items per category. Costco may have 1-2 options, while Sam’s will have 3-5 usually e.g. brands of mac and cheese, Costco has one brand of organic (Annie’s) and one brand of non-organic (Kraft), Sam’s will have maybe one or two of each.
Has self-checkout (you only have to swipe your membership card so you could hypothetically share your card…not that I would ever do that)
Decent enough food court with some different selection than Costco
Membership is $10 cheaper than Costco
More soda choices in the food court
Almost always significantly less crowded than Costco
Sam’s Club Disadvantages
Employees are almost universally less friendly than Costco
Return policy requires a physical receipt even though they can look it up (they will do a fixed number of returns without a receipt before blocking you from returns w/o a receipt).
Clientele is one step up from a Wal-Mart
Gas is more expensive
Very rarely on-the-ball in the food court - they are always running out of things
Prices are usually a little bit worse on average
BJ’s Advantages
Pretty good diversity of products – much closer to a traditional grocery store
Can use your regular credit cards
Has self-checkout
Stores are much more likely to not have many people in them
BJ’s Disadvantages
Not usually the best prices on things compared to Costco, but better than a non-bulk store
No real food court
You feel sad going in there
I rank them as such: Costco > Sam’s Club > BJ’s. If you have a choice, then I would go with this flow chart.