This is not totally true.
One of the main problem with photo equipment is the cost of shipping. Most people are not willing to pay $250 to get an enlarger shipped across the coast. So it is all local supply-demand.
Also, because people see analog photo is dying and there were some very fantastic past deals, they are very optimistic about picking some pro photo equipment on the cheap side. Some of the them are clearly not realistic.
I have a couple of Saunder LPL 4550 XLG complete with color heads. I posted here and tried to get $450 for it. There was only one response and he still has yet to contact me again. I'm not eager to post again and sell it cheap. I'm going to post it again when I get a chance, but I'm not going to sell it for lower than $500. In a couple of year, they may worth more than $700. They are in great shape.
If you do not want to spend that much money, get an old Beseler. Or even some old Omega. But they are not the same quality.