I bought a Giant 200 amp TIG from ebay, it lasted for about 3/4 of the chassis welds till the gas solenoid valve stuck shut and the tungsten burned out almost instantly.
Couldn't get it replaced as it had come from China, and couldn't get the valve replaced as it was a crappy chinese copy part.
Lesson learned, don't buy cheap chinese, unless it comes with free prawn crackers. After that I was GIVEN a second hand SIP Handymig that has been faultless for the last 18 months no matter how much I abuse it.