experiment with ceramic.
If you want to experiment with a ceramic smoker for "cheap" (cheap is relative, of course), get yourself 2 large terracotta pots. Alton Brown did a show on good eats showing how to do this. He used an electric hot plate, but you can use charcoal if you can keep the temperatures down, and can get enough air through the bottom. You can build one for less than about $50.
My poor dialup it worthless, so I can't watch it, but I think this is the youtube of the show:http://youtube.com/watch?v=_Ka2kpzTAL8&feature=related