The CD Warehouse is kind of like a used bookstore, it's hit or miss.  I have found some great CDs here on some occassions, and on others I felt like I was flipping through a fourteen year old girls CD collection.  However, they have no problem taking your used crap that you no longer listen to, no matter what it is.  You can also redeem your old CDs for store credit, which earns you a little more money.  The CDs run from about two to ten dollars.