Was gonna ask about this myself- will be needing to bend some 1" 12g. I can find somebody in my area to do it, but I was considering buying one of these from
Harbor Frieght. Wouldn't give me any control over the radius, but I'm not that picky, and I only need to put a mild bend (45 deg) in. Seems like could also be useful for making custom exhausts. I've seen some guides to mods you can do to one of those (mostly a clamp on the die to prevent the tube slipping) that seem to end up giving good results.
$99 (before any coupons) and ability to bend up to 2" pipe (and down to 1/2", in .25" increments) seems like a worthwhile tool to have around. And I can probably get some karma by putting it on loan at the workspace I belong to.
But if it won't do the job I need, its obviously not worth it...