You do "get what you pay for." if you plan on doing a lot of welding get a miller 211, 180, or similar. My brother just got a miller 211 with autoset and it works very well. The new 211 is also much smaller than the older one, making it even better for storing in our over crowded garages. I have a miller dvi2 mig, and a miller syncrowave 200 tig, and love them both. But if you want something a lot cheaper, I have been pleasantly surprised with the Lincoln 100 using flux core. They don't have the amps to use solid wire but if you take your time, you can do very well with the 110v lincolns. I found the Lincoln 100 for $100.00 on craigslist. If you chose to buy a used welder, insist on trying it out before you buy it.
I bought a Miller 211 essentially as a hobby welder and im glad I did. Its not cheap, but its a great machine and will probably pay for itself a few years down the road.
I have a little harbor freight backup that I use in the field and while it works, its not exactly pleasant to use.