My wife brings stuff to Half-Price Books periodically, usually getting close to nothing. One time I decided to help her out as we had a lot of old DVDs and CDs we didn't actually use. My wife was extremely excited when they gave us over $80 for everything. I asked about why it was for so much, and apparently a couple of the CDs I had brought in were extremely rare and quite sought after. The only one that I remember was a demo CD with only four songs on it, but apparently it was worth a lot to someone.