I got a remaindered hardcover copy of Khai of Khem from Barnes & Noble for only $6. It's a good book, though I found the structure a bit annoying.
It's about a guy named Khai. He's a general of the armies of Khush. He was originally from Khem, but the pharaoh of Khem--who's a psychotic alien/human hybrid--murdered his family. Now Khai seeks revenge. Unfortunately, his soul is separated from his body and is propelled into the modern world. Somehow this enables him to go back to his own time with knowledge of iron weapons (this is set in the bronze age), chariots, and saddles.
The story starts with him getting his soul separated by evil necromancers. Then we see him in the modern world. Then we see his life story n the ancient world (during which time he knows stuff from the future world for no apparent reason). Then the story catches up to the beginning and his soul is drawn back from the future. Then comes the final battle with the pharaoh and his evil necromancers.
I'm really not sure how Khai knows about iron before his soul travels to the future. It just doesn't make any sense to me. It's still a good story though. Good enough for Khai of Khem to get four yo-yos.