We used a mixed gas at the old shop, C02 Argon mix I think, it did a fairly good job on most everything and was cheaper than straight argon.
The mig machine I learned on was a beast too 3 phase and more power than I ever needed. It was also old though, so not much in the way of bells and whistles.
I looked at the Handler 187 at TSC, it was 659, and you can get a 10% off coupon that will knock it under $600. It comes with a regulator and hose but no tank. You can get a small tank at harbor freight for $75
http://www.harborfreight.com/cpi/ctaf/d ... mber=92807
Toss in an autodarkening welding helmet for 50 bucks or so and your setup for less than $800. Less a spool of wire of course, I think it comes with flux core though, so you could be welding straight out of the box if you wanted. And that is for a real decent welder, if Im not mistaken, hobart and miller are essentially the same welders.