If all you are going to power is teh 200DX, you don't really need a 50 amp outlet.

I was going to re-do teh power out to my garage until I measured the current for my 200dx....now I just run a 10awg SOW extension cord from my dryer plug in my basement out to the garage....I believe it is abotu 110-120ft of 10AWG and it doesn't even get warm. I have yet to tip a breaker (30A) and cannot detect any temperature change (by hand) on the cord.

I know it sounds odd, but that is all it takes. You could just use a 10awg extension cord and cut off the ends to run teh welder wherever you want.

by the way, I have a full 240V (242 actually) which does help a bit on the current requirement.