The jokes about warehouse clubs are pretty easy to make. The idea of buying a 3-gallon tub of mayonnaise and rushing to use it before it goes bad may not seem like many people's idea of a good bargain. But warehouse clubs like Sam's Club, BJ's Wholesale Club and Costco offer major discounts to customers on several name-brand and high-quality foods and household goods. They're able to offer savings by keeping costs low, making deals with suppliers and selling products in those ridiculously large packages. For an annual fee ranging between $40 and $50, the clubs sell merchandise at profit margins well below retail competitors [source: Warehouse Club Focus]. But not all bulk shopping deals are created equal. In general, you want to buy things you'll actually use, and won't go to waste. To avoid spending the rest of your life eating from the same tub of ranch dressing, and to take advantage of some good bargains, read the following list of 10 things you should buy in bulk.