I've been keeping an eye on a welder going across craigs list. It is an old SP-150 220V MIG welder. from what I've ready on one other board (the only useful information that comes up on google) these are rather robust machines for the price. He originally wanted $650. the information I came across said the newer counter part (SP-175) retails for around $750, meaning this price is a little high (and more than I wanted to spend) He has just re-posted it for $500 (still too high, but it shows that he might be getting toward my price eventually) My question: Where should I pull the trigger? my other information suggested spending only $350 at most and a few people said buying a used welder was insane because it would cost more in the long run. Let me know what you think.