we had one of those in high school metal shop. they work surprisingly well, and they're easy to use. you have to bend it in small increments, so it's tough to over bend the tube, unless you just keep running it through without checking it. can't imagine it'd be cheap to buy one, though. lots of big metal parts. i would think you might be able to make one, as long as you could find the steel rollers. if not, there's gotta be a local high school/trade school that might be able to do it for you. maybe trade them some t-shirts or something.