About 10 years ago at an antique mall, we saw a blonde Dumont is excellent condition (don't know if it worked though). We passed on it at $60. Later, we thought better of it, but when we got back there, it was gone.
At another booth, however, there was a Predicta (princess?) that looked like it had been set out for trash, ready to fall apart. They wanted $300. um...right.
Some time later, at the same antique mall, we got a Stromberg-Carlson floor model 15" B/W set for about the same money. Looks nice, but haven't had a chance to work on it.
Our best antique mall find was a perfectly preserved vintage TDC stereo projector, for the type of 3-D slides my wife takes. Though it was in its case, she spied it and made a beeline for it. From 20 feet away, she recognized the little TDC logo on the top of the case. With the usual 10% discount those places seem to have, it came to $27. She couldn't stop
all the way home.