I have a Lincoln SP135T MIG that I make all of my parts out of. It's big enough to do up to about 5/16" steel, and I've welded up tons of stuff at 1/4".
they'll run you about $500 at most places, then you'll need about $250 worth of extras.. Gas bottle is about $150, good welding mask is about $40 ($100 if you get auto dimming :thumbsup
, more wire $30 a roll, anti-spatter gel is a few $, good welding gloves, $20....
so expect to spend $750-1000 for a decent MIG setup. double that if you want to go to a TIG setup.