Here is what im trying to figure out. there must be a reason why the home depot ones are cheaper so my question is i can get a brand new 180 hd for the same price i can pick up a 2 year old sp 175 plus. Does anyone know the difference between the two? Also i will not be welding alot just exhaust here and there and misc. stuff and occasonally tube steal for roll bars or other stuff thats equivalent. What do you guys think would be the best idea for me? both come gas ready just need a tank. I know nothing about welders so i hate to jump inot something and grab the wrong one.