There are a lot of stainless headers coming out of China now and they seem to cost 1/2 or less what we're used to paying. I think it started with ricers, then larger cars and now car/truck V8s. I don't know if the grade of stainless is quite what they claim, but they certainly aren't mild steel. If you search for Speed Daddy or similar import headers there are lots of stories of leaking welds and general poor fitment. That being said, a roll of stainless weld wire is $30 and if you have a few hours to screw with them it could be a good deal.
If only they had a Tri-Y or even "afterburner" style.