its all relitave as stainless tig rods are also more expensive than mild ones.
if you can afford an ac/dc tig and plan to use it for lots of jobs then go for it. i have one and use it all the time.
what i would say is dont spend loads of money on a tig welder that you only intend to make an exhaust with, then put away for ever.
at the end of the day. if you want a tig just go buy one
remember we are not your wife you dont need a reason to have one on here. you can have one because its a cool thing to have rather than a thing to do a job with
i had to have one to repair car body work wink wink.