Text books online

College text books can be expensive, my bunch that is and was in college always tried to find their books online, used whenever possible to save money. Then when they had completed a course, if it was one a friend or a sibling was not going to take in the very near future they'd sell books from those courses online instead of back to the college bookstore. Most times they ended up with enough money from their old text books to buy the books needed for the next semester.