An auction house in North Carolina has listed that a rare Big Briar Ethervox MIDI theremin will be available for sale this weekend. These extremely rare instruments were produced by Big Briar around 1997-1999. It is believed that only ~50 were produced. The Ethervox uses a digital sound generator to produce various timbres and traditional analog electronics to sense proximity. The Ethervox is unique in that it can output both CV and high resolution 14-bit MIDI signals via a "snake" box.
The auction listing claims the estimate to be $1500-$3000, which in our opinion would be a substantial discount from it's actual value. Best of luck to all the bidders!
More: Big Briar Ethervox MIDI Theremin (BrunkAuctions.com)
Related: Big Briar Ethervox MIDI Theremin (photo gallery)