I just bought most of my text books online. I saved about 50 if I had purchased them all new at the college bookstore. It was about 50 more than if I bought every single book used at the book store (but the chances of that are basically zero). And the order was so big, shipping is free. It will take about a week for them to get here, so I am going to head down to the bookstore and purchase the final few that I could not find online, which is perfect, because it gives me textbooks to read in the mean time.
The only bummer is I should have done this last week. Oh, well.