The wonderful thing about Cheapbooks for us savvy book shoppers is that it acts as a book search engine, if you will. It is your one-stop shop for discounted books of all kinds. All you need is an ISBN number. Plug it in and it will give you various options and prices on different websites for buying new or used books or renting a book.
If you're looking for cheap textbooks, simply input the textbook ISBN given to you by your professor and the site will lead you to websites selling that book for a reduced price. If you're looking for a book without an ISBN, search the title and various years of publication with their respective ISBNs will show.
It's really easy to use. And it makes being frugal that much easier.