Textmania has a lot of used textbooks availabe! If you found out that all the used copies of the textbook you are looking for are all sold out in campus bookstore, you should go check out textmania! But if you are looking for new copies, I think you should just buy it in campus bookstore as it is more covenient, the new textbook in Textmania is just a dollar less than that of the campus'. Moreover. if you want to sell books, either sell it online or go to the class. Textmania only give you 20-30 bux for a $100+ book!