The best way to save money buying used textbooks is to use a textbook price comparison service. But there is a step you might overlook that could save you a lot of money. If you are using a price comparison service don't overlook pricing earlier editions. Step one in price comparison is to search using the ISBN to get the lowest prices on the latest version. Next search using the exact textbook title. This should returns all the editions of the textbook and their prices. Prior editions will be considerably less than the current edition.