You can very well buy a mig-gun for $200.00 even @ Wal-Mart,but it will not be good enough to weld a roll cage. Not if you want it to hold up if ever in a crash. You can Mig weld a mild steel cage with a good Mig and it will hold if welded right. You run a bead down hill (welders know)with a mig,it won't hold!!!! Like someone said earlier you can buy a $200.00 arc (220 amp)and weld any M.S. cage and it will hold better than any mig weld.Take you forever to weld it,but will give you a stronger weld. I was a supervisor in the weld-bay @ Varco-Pruden for 14 yrs. been a welder for 25+ yrs.

BEWARE of who you trust to do any welding on your Race-Car. A poor weld is about like sticking bubble-gum on your cage or what ever you have welded,just because it is stuck on it does not meen it will hold.