Now that we're replacing our regular book library with Logos, where have you all successfully sold your regular books (hardcover/softcover)?
To sell back dead tree textbooks... Amazon.com [:)]
I do this in tentmaker fashion. Some books work well on Amazon, some do not. Amazon does not have a bottom price, you can sell a book for a penny. That's right, one penny. Except that you'll pay Amazon about $3.00 for that. Amazon's minimum commission will gobble up most of your postage money. If a book sells for under about $7.00 use Half or eBay. Admittedly, both sites are plagued by bottom feeders who want the book for nothing too, but if you don't hold your own, you will not make anything.
eBay and Half rely on a less than perfect listing system. If your item isn't in their catalog of ISBN numbers you will pay through the nose in fees on eBay unless you sell them by auction.
I sold off many of my print books to help pay for Logos. Still have some to go. Summer is absolute deadly slow. You can list your books now but don't hold your breath.
Books can take up to a year or more to sell. I suggest you don't keep dropping your price. Good books will sell.
One more thing. Be scrupulously careful about listing descriptions. Any underlining, highlighting or marginalia needs to be mentioned. Never list books with this above good condition. Very good or better are reserved for clean books with no damage or markings.
And pack well. The post office is brutal on books that are shipped as Media Mail. They often knife open the packages to catch people who misuse this bargain rate shipping method. And they don't seal the package when they are done. If you don't pack properly your book will arrived damaged.
I hope that doesn't scare anyone. I've done this for years; you have to be proactive to make any money.