I hope to find a unit at a reasonable price. Some of the transmitters
I listed originally sold new for less than the cost of a decent piece
of test equipment; so wouldn't expect used ones to be very expensive.
Bear in mind I am looking at "low power" models, not the high-power
behemoths. Don't know any hams who really want to output 50 kW,
although I do suppose it would serve to keep winter snow off the roof.

Radio stations have been known to simply scrap their old transmitters
as they upgraded to later models. Not much demand for the large older
units. The situation might be different for FM broadcast transmittters
though.