I have not seen one at the convention before. It's definitely extremely difficult to find though. At auction, you should be prepared to spend at least $100-$150 if you can find one. Took me a couple years to track mine down and I had an alert set up for it on
eBay. That was the only one I've ever seen on
eBay too. And no, it's not for sale.
Good luck! The hunt is half the fun.