(Pentax)Dude! How many wierd lenses do you have!?
They show up on eBay fairly regularly, so they're not that difficult to find. As far as I know, they don't have a great reputation (check out the lens review section of this site).
I've been mildly interested in checking it out, but I won't insult either of us by telling you how much I would want to pay for it
Just put it on eBay with no reserve and see how high it goes. The way old Pentax lenses are selling lately, it will porbably sell for 200% of what it's worth.