My Brother in Law told me about a school district auction that took place a couple of weeks ago. Carpet cleaning machines that were last years model with 10-20 hours on them sold for 10% of new. Apparently they go buy a new one if there are any issues with machines. Metalworking machine went dirt cheap too. Wish I could have been there. More tax dollars down the drain. Steve
Our school had a few of that same class machine if that's the machine I think you are talking about. Big 600 lbs transform machine that does Tig and Stick. All 3 of their machines are broken at this point and they don't plan on fixing them as far as I know. They have been replaced with new inverter machines.
The HF contracts would tend to burn out and/or need adjusting but most common was the diodes would tend to burn out and need replacing (so I was told). These are machines from the 1980's and the school I think has had some since that time. They have had to replace the diodes many times over the years. It's got no electronics (transistors and circuit boards) - just transforms and relays - and the full schematic is in the manual.
I've heard of those machines going for $50 in working condition at surplus auctions. They are just so damn big for the power and features that most people don't want to deal with them any more. Just getting them home is a problem at that size which is why they don't sell for a lot more.
I wouldn't be surprised if that $375 machine is working. If not, a few parts like some new diodes will likely get it working. Though I have no idea how much those diodes might cost.
It was probably the best TIG machine in the shop. It produced an extremely smooth and easy to control arc. I wouldn't mind owning one if I had the space (which I don't) and could deal with its size.
That Hobart if it comes with the Mega-con feeder was near $8,000 bucks in late 80's money (the best Delta-weld 650 ran $5,500). A time when gold was really king and you paid for it. The parts inside are now supported by Thermal-Arc (except the lump, if it goes to ground you're toast). When outfitted with an RVS torch and separate work lead you can move the torch up and down very quickly and it will hold the arc length (you'll look like you need medication if someone sees you though).
The Lincoln would be of interest to anyone doing EGW, SAW, FCAW or CC flood welding, as well as Arc-gouge. It will handle up to 1/2" stick (1200amps) for forge die flood welding. You might take a small sub station out if you hook it up wrong though LOL.
Don't know if they are still there but Chicago Ox-weld may be interested in the Lincoln (they used to do a lot of flood welding).