Air compressor sale

Compressor rpm is as much a factor of pulley size as motor rpm
I learned a lot about that one with a'50s champion compressor I had at my old house.
I thought a bigger motor might help air output, not really. I replaced a 1725 rpm motor with a 3450, I ended up having to replace the motor pulley with a much smaller pulley to then slow down the pump.
I now have (and have had for ~20 years) a 2 stage, 4 cyl pump, 5hp 80 gallon upright Emglo that I bought at the time out of the local paper. About 5 years ago I had a valve issue so I tore it down and overhauled it/all new valves, new gaskets new rings. And as good as new again.

I've been looking for a similar compressor for my kid, and have been blown away at asking prices. I was just emailing back n forth with a guy in my area that had a newer champion 2 stage on CL I don't know what model but it's a 3 hp 2 stage upright, and he threw out a $1500 asking price saying it's 1/2 price of the current version, I don't think he's comparing apples to apples. But that's 3x what I paid for mine 20 years ago.
Which at the time a then local compressor dealer offered to double my money in cash "right then" when I went there looking for filters for it.