If it came up in my area, I'd pay about $50 for it. If it happened to be a desirable set that I had been looking for awhile, then the very limit would be at or below $200. Craigslist seems to be where most tv collectors look for sets, so that would be the best place to put an ad up.
The larger console models tend to sell for less, basically because tv collectors only have so much room, and those big sets really have to be something special in order to sell for much.
The early television museum has this to say on the subject of the values of older sets, which pretty much falls in line with what you've heard here:
http://www.earlytelevision.org/how_much.html