They're worth what someone's prepared to pay for one. Pretty rare here so demand is high. Engine parts shared with full-size watercooled NSR50/80's but the rest usually has to be found in Japan.

I know a few people with them. Check out My Gag Page or The Gag Bike Forum.

This Nastro one (non-standard paint) belongs to my wife, that's me sat on it in the other pic. The Rothmans or Repsol ones are the ones to have, and the 80 is more usable although the 50 will do 50mph no problem.