I've seen TurboCad for fairly cheap. I think you can still get it free from IMSI. The problem I have with that is that big ad bar that takes up a bunch of space. Basically says "Buy Me, Buy Me, Buy Me". Very annoying after a while. I've also used Drawing Bd, Auto Cad and someother cheesy cad. They are basically all the same with a few differences between them. If you're not familair with cad procedures it will take a while to pick up no matter what you get. Just my opinion.
Edwin