Or, to put it another way, the price of items in the store is roughly equal to the cost of goods plus their distribution and overhead.

I find that really hard to believe, since I find it's very difficult to get a good deal on anything at Costco. I'm sure there are some good buys, but that's true for every store.

Costco either don't have much buying power, or other companies are selling at a loss (which we know isn't true, since other companies are posting record profits all the time).