We have about 100 plasma cutters where I work. Hypertherms, Lincolns, and Thermal Dynamics. Hypertherms are top of the line in hand units. The first thing to look at is consumables. Does it come with any new stuff? Tips, rings, insulators etc... Check the lead very carefully. Check for electrical tape. If a wire was nicked or slightly burnt...that is fixable. A hole in the air line...nope. Barbed splices will just get you some ugly shrink tubed frankenstein. Smell the handle. If it smells burnt make sure you know what you are getting into. Electrodes and micro switches and triggers can be replaced but at what cost? Some of the older ones had a microswitch at the insulator that got messed up alot. For our companies cost we pay around $500-600 for a whip. Granted these are probably much more expensive systems. Check the guys tip out also and ask what general use the machine had. I have seen a lot of people using a gouging tip as a dragging tip and arc out leads and boards. Check the regulator and Air dryer. Also some of the grounds on older plasmas were direct soldered inside of the unit so if the cable looks fucked take that into account.
