cheap welder for fun and profit

[Captian James F. Awesome]

I used to do MIG, TIG and oxy acetelyne welding back in high school shop class (long time ago..) and want to get back into welding. Can anybody make a suggestion on a cheap protable MIG welder? Can you get one that does a decent job that runs on 15amp house socket so I can take it around places, or is there no such thing. I would mostly be using it for thing like butt welding exhaust pipes and stuff like that. I guess I really never welding anything less than 1/4". Would a crappy MIG welder still burn though exhaust pipe?