I made the mistake with my oldest, Aly, of buying all of her college books from the campus book store-ouch! That was CRAZY expensive! You can save big time if you shop around online, like we're doing with my youngest, Gracie.
My favorite place to shop? Chegg, because you can rent! Another source that I discovered is SlugBooks. It'll compare prices of several online stores for the best rate for renting or buying. For more ideas, check out the suggestions from Her Campus.