When Ds started college I just about went into cardiac arrest seeing the college bookstore prices for textbooks. I think we purchased the first quarter's books at the bookstore, but by the time the second quarter rolled around I decided to do some online checking into alternative ways to purchase. Boy, am I glad I did! I'm sure I have saved a minimum of 50% over the cost at the bookstore - of USED books, to boot.
My favorite tool to use to research prices is DealOz.com. Just type in the ISBN number of the textbook and up pops numerous places to purchase. The search can then be sorted various ways, by price, new, used, etc. I have saved so much money using this website and have purchased his textbooks through several different sites over the last 2 years -Amazon, Barnes & Noble, Ebay, along with renting books on several occasions. Textbookstop.com has been my favorite to rent from - they made it the easiest to return, by sending me a prepaid envelope to mail back the book in. Chegg and the other one I used (I can't recall who it was off the top of my head) for renting, I had to find a box of my own to send back in, even though I was able to dowload a prepaid return shipping label.
Even if you don't use this resource, Amazon.com is great for textbooks much cheaper than the college bookstore. Ds prefers his computer course books (his major) to be new (but has used e-books on some classes) because he wants to keep the books for reference. For his general courses, we have either purchased used or rented. Our neighbor just spent $900 for textbooks for her Physics major classes! But I commented to her on Facebook to check out online prices and she found a couple of the books much lower, so is returning the books purchased at the bookstore, and buying the books online now.
For example - the 3 textbooks Ds needs for this quarter came to $294 new or $221 used at the school bookstore. With the online search I have found I can buy the 2 computer class books and the English class book for $130 total. This would be e-books for 2 of the books and an actual textbook for the other class. Even if I got him actual books for all 3 classes, the total would still be quite a bit less than the bookstore, at $156.