keep an eye on thrift stores. A Friend of mine picked an orbit archival washer, that was basically new, for $7. I have found contact printing frames ranging in size from 4x5 to 11x14 for $2 per!!! I found a signed copy of dick Arentz's British Isles for $7 dollars. amber 500ml glass bottles for $0.50 a piece. Most of the time the funky obscure equipment goes for super cheap, because nobody knows what it is. Things like densitometers, mounting presses, light meters, horizontal enlargers etc... all go for about 10% of the market value (usually). I once found an 8x10 enlarger, albeit in horrible shape, for $75.
The trick is to hit all the shops on a regular basis, and patterns will emerge after four or five months. The key is persistence and having an idea of what things are worth. Also, be sure and test it before you buy it, a burned out enlarger bulb may result in it being half off.
Yours;