By Jessica GrossYou already know how expensive college textbooks can be. But buck up, because we have some loopholes for you! There are several ways to access course materials other than through your campus bookstore, and these alternatives often don’t require shelling out hundreds of dollars.Buy Books Online—and Buy Them UsedFirst, you can buy your books online, where prices are often much lower than those you’ll find in your campus bookstore. The National Association of College Stores explains that textbooks are cheaper online because publishers abroad often mark down their books’ prices for wholesalers and retailers, who can sell them via the Internet.How much can you save by purchasing textbooks online? Depends on the book, but a 2008 report by the New York State Comptroller found that SUNY and CUNY students could save nearly 40 percent on course materials by buying them online.Several websites specialize in providing college textbooks at reduced prices, and we’d recommend checking each for the books you’re seeking to find the best deals. Our favorite online textbook retailers include Textbooks.com, Half.com, AbeBooks.com, and Amazon.com.To find the best deal on the books you’re looking for, follow these tips:1. Buy early. Start hunting as soon as you have your list of required course materials in hand. This will ensure that you find the lowest prices available—before all the other students in your class, and at schools across the country, claim the cheapos.2. Buy used. Online retailers are often great sources for used books. These versions can be far cheaper than new copies. The websites usually list the condition of their used books, so if owning a crisp-looking copy is important to you, check the descriptions before you buy. Most of the time, though, you’ll need these books for only a semester, and wrinkly pages read the same as just-printed ones.3. Sell back. If you finish a course and no longer need the books you’ve purchased, sell them back. Some college bookstores buy back textbooks at way below their list value so they can resell to students the following semester. But some websites offer better deals. Textbooks.com, for example, offers a guaranteed buyback price on some of their selections, meaning that you can determine what you’ll gain back at the semester’s end before you even make your purchase. But you can also make a decision at the end of the course: Textbooks.com has a buybacks page, as does Half.com.Textbook RentalsIf you know you won’t want to keep your course materials at the end of the semester, textbook rentals are a great cost-saving option. A number of sites allow you to order books for a finite period of time.According to the Wall Street Journal, textbook rentals almost always save you money. “In almost all cases, renting is cheaper than buying the book either used or new. True, if you buy the book you may be able to recoup some money by selling it at the end of the term. But textbooks are continually updated, so a student who waits to sell an old textbook could find no buyers if a new edition is coming out,” the Journal advises.Our favorite textbook rental sites are Textbooks.com, Chegg.com, CampusBookRentals.com. You can also use Textbookrenter.com to compare prices among different rental sites and to find out how much you can expect to save versus buying new or used. When you decide to rent textbooks, keep in mind that each website rents for different lengths of time and check your finals schedule to make sure you won’t be hit with late fees. Chegg.com’s semester rentals are due 125 days from the order date, for example, while CampusBookRentals.com gives you 130 days from the order date.Textbook rental prices vary by book, so compare your selections on these websites before you decide. Also, familiarize yourself with the company’s return policy—how you’ll ship books back at the end of your rental period—to make sure you understand the procedure.