Many goods are cheaper when purchased in large quantities. Obviously, you want to stay away from things that will spoil (In other words, don't buy milk in bulk). Some bulk purchases go wrong for reasons you couldn't possibly predict: That pack of 500 blank DVDs seemed like a good idea at the time -- until they started collecting dust when everyone switched to flash drives. Win some, lose some.
How can you make sure you win more than you lose? Make an organized space in your house to store your bulk goods. Sturdy basement shelves work well, as long as things stay dry. It can be difficult if you live in a small apartment or a house without a storage area. You might have to repurpose a closet or even buy (or build) a free-standing cabinet.
The best items to buy in bulk are paper goods. Toilet paper, paper towels and printer paper never go bad and store easily. It's also sensible to stock up on cleaning supplies, garbage bags, soap, shampoo, and laundry detergent [source: U.S. News and World Report]. These are things you'll always need and will certainly use -- and won't go bad.
Bulk purchases can account for a wide range of savings, depending on the products. Buying large packs at the grocery store can save you five to 10 percent. You can buy even larger quantities at club stores like Sam's Club or BJ's, but the cost of the membership eats into your savings. Don't forget that you'll save some money and time by making fewer trips to the store, too.