Well, we sold the 1946 GE projection color wheel Model 950 for $14,000 around 10 or 15 years ago, and the buyer re-sold it for 150,000 pounds sterling to an overseas Museum, not too much after that....so that might have been the most expensive TV sale going...although I'm not sure what the plexiglass TRK-12 sold for.
http://www.earlytelevision.org/ge_1946_prototype.html
...where are those TV museum's with unlimited cash???