I think you're about a million times more likely to find a good deal on a PVM in Baltimore in general than you would be at some con.
Do remember that these were not designed for gaming, they were expensive pro gear. The bigger your city the better your odds at getting one. Rual America is Poor America. Maybe a Christian TV station, that's about. In the city you have duplication houses, network affiliates, production, FX, etc.
Also, these things sat around for a decade or two before you started looking for them. Don't get discouraged just because nothing turned up in the extremely brief span of time you've been looking.
Btw, I got a free 20" Toshiba today. Flat tube. It even has more than one component in. This should do until I get my JVC pro monitor back up and running.