If you are asking about the quality of the Beef at Costco, price is about the same as Wal-Mart or insert your grocery store... But I have never encountered USDA Choice anywhere that is better, most other places are not even comparable for me. Most of the time their gas is 7-10 cent/gal cheaper. If you lived close enough to one that had gas, depending on how much you buy a year, it might pay for the membership.
(Teaching moment for you all for me...Costco is not a person...so it is not their gas, right? It is there beef?)