I have one I bought a few years back. Still unfired in the box. I paid about $400 for it at the time. Check GB, it'll give you an idea of what they are asking for, then monitor the auctions to see what they actually sell for. Kind of regret not buying a pair of them, they do seem rather unique. I "inherited" a few thousand rds of 9mm reloads that just wouldn't cycle a semi-auto so I thought a 9mm revolver would make good use of them. Still have'm just haven't gotten around to shooting it.
Sorry I couldn't be more help.