The mark-up on a used book is several hundred percent. The bookstore, which already made $20 on that book once by selling it to you new, buys the book back for about 25% of retail. So, when you sell back, they’ll give you $25. They will then sell the book as used for 50-75% of retail or $50-75. That makes them up to $50 more dollars on that book.

They will buy it back again for $25 and sell it again for $75.

In just three semesters, the one book has made them (20-25+50-25+50) $70 — selling that same title three times as a new book would have made them only $60 and the cost to put three in inventory would be significantly higher. In this way, the percentage of return is much higher on used books.

You can get considerably more for your used books by selling them yourself on half.com or amazon. If it’s a book that retails for $100, you can expect to buy or sell that book used on half.com for less than $50. It’s very possible to get free textbooks this way. You buy the book for $50, use it for class, then sell it for $50 online.

The really good thing about half.com and amazon is that they don’t rely just on titles in use at your college – if your college changes editions then your bookstore won’t want the book. Someone online may still need that edition that you have.

I know a couple people who make a decent income asking friends for their books that the bookstore won’t buy back. They then sell those online. The book cost them nothing, everything is profit.

Used textbooks is a highly profitable business.