If you want extremely cheap, just troll ebay for some of the older completely manual film bodies. Things like the pentax k1000, canon AE-1, and such come to mind. If you look long enough, you'll find some ridiculous deal that comes w/ a 50mm lens. It will be plenty to satisfy a curiosity into film and find out if you like it or not. If you want to stick w/ canon and want to use the lenses you already have, go here http://en.wikipedia.org/wiki/Canon_EOS
and look at the list of film cameras. You ought to be able to find one of those on ebay for a reasonable amount.