Chelsea emailed in with the following tip:
Last week, I discovered Amazon’s trade-in store, and ended up having almost 400 dollars worth of credit between six text books! After researching what the books were worth, I found that Amazon was offering me a very fair price. I was able to ship the books for free and quickly received the credit in my account.
Besides text books, Amazon also accepts electronics, movies and television series, video games, consoles, and accessories for trade. I would highly encourage MoneySavingMom® readers to check out this program. Paired with free shipping and price matching, the store credit could really come in handy.