Students are not the only people you can buy books from. In fact buying from the  professors in their offices during the day can be one of the best ways to earn extra money before you buy from fellow students in the afternoons and evenings. With professors you do get paid more with their books than with students--ask your recruiter.

Before you buy from professors make sure you switch from DGV (double guide value) to SGV (single guide value) by going into your preferences under the “more” tab. There you will see “single” and “double” next to wholesale pricing. If you don’t then you will be paying twice as much as recommended and you will lose money.