Costco Wholesale Corp. (NASDAQ: COST) warned Tuesday that profit for the quarter ending in August would be "well below expectations." That statement comes as a surprise. The company that should be benefiting greatly from customers buying in bulk and "trading down" to lower-priced goods, issues lower guidance in the thick of a depressed U.S. economy.

The wholesaler said that analyst estimates of a $1 per share profit would not be met, and then quickly talked about how rising energy prices would be to blame. Costco kept its prices steady even as its own costs have risen. It also experienced diminished profit in gasoline sales. The good news is that Costco's same-store sales have not trended downward recently. The company is still making a healthy profit, but the question is why it is holding many prices steady even as costs and transportation backend prices rise?

One answer is Wal-Mart Stores, Inc. (NYSE: WMT) and its Sam's Club operations. While in a Sam's Club just this past weekend to check out prices, I was amazed to see that once inside the store, any semblance to a credit, mortgage and credit crisis was gone. Prices were lower than ever on many items, and Wal-Mart faces the same kind of financial cost pressures as its competitors. It can afford to keep prices lower even through tough times, though. Costco has to keep up, and as a result, its profits will take a hit.