I was just doing a bit of research on them because I wanted to get one off ebay. Lee Freidlander
has some nice shots with one. It looked like the older ones (they go back to the 50s I believe) will get around 1200 and anything decent/newer will go around $2000+. So that put it out of my price range. I would have gone for it if it was around $700, but they're pretty pricey. Good luck.
I did contact David Odess who repairs them to get his opinion and he was very forthcoming with info. Maybe contacting him will help: http://www.david-odess.com/