Have you heard of Amazon Student?
It is a service offered through amazon.com that basically allows for students to get the "Amazon Prime" membership for free. All you need to sign up is your school e-mail address (.edu).
I signed up for it this week and I wish I had discovered it sooner. It allows you to get free two-day shipping on textbooks and a lot of other items! When I signed up for it, I also got an offer to sell back a textbook that I bought using Amazon last semester. You just follow the prompts and ship your book (FOR FREE!) back to the seller, and get a credit for the refund amount.
How easy is that?
If you are a student, I highly recommend signing up for Amazon Student.