In 2002 I spent around $800 on a Millermatic 175 with regulator, tank, and cart. It's been absolutely great and reliable as a hammer. Other than a nozzle or two, I haven't had to replace any parts, but I'd bet most of them are still available from Miller. The 175 has been superseded at least twice with newer machines, but the cost has risen significantly.
I know a couple guys who started with generic 120 volt welders (Summit Racing & Eastwood), but they ended up getting Millers within a couple years. One of them does a lot of fabricating and has used the heck out of his 175, but it still works well.
As for flux core vs. shielding gas, it's night and day, mono vs. stereo, black & white vs. color...