I just listed a bunch of audiobooks on cassette.  If you order 1 for the regular 2 credits, any additional ones will be one credit (so the first 2 will be 3 credits, 3 will be 4 credits, 4 will be 5 credits, etc).  There are also some one cassette mysteries that I will do better than that depending on how many you want, just let me know which ones you want and I'll let you know how much. Among the regular audiobooks I have (unless they get requested in the meantime are The City of Ember and The People of Sparks by Jeanne DuPrau, and all three His Dark Materials by Phillip Pullman (The Golden Compass, The Subtle Knife and The Amber Spyglass) performed by Phillip Pullman with a full cast.  Also many Mysteries, some Fantasy/Sci Fi, other childrens including some classics, and just some misc.