Jordan,
Look around for a used one, someone is always looking for cash and I have seen Millers and Lincolns go for about $300 that were nearly new.
I would go for the 220 1-phase myself. You can weld up to 3/8" material and down to 24 gauge sheet metal. the 110V models are fine for sheet metal, however barely weld 1/8" material prior to getting hot and tripping the thermal breaker.
With the 220, you can make up a long extension chord and plug it into the dryer or range outlet (did that for years prior to getting the old garage wired)
I would RUN from anything from Harbor Freight. The Clark units are ok at best. I would stick to a Miller, Lincoln or Hobart. There are hundreds of small lincoln SP units out there.
