Adam...They are relatively difficult to find, and they have been counterfeited (as far back as the 1970's). Complicating matters is that with their unusual surface, it can be challenging for the graders to get it right. I have purchased several lots over the years from the larger auction houses, which have included some of these counterfeits...Most of the auction houses have made it right....They are relatively stable pricewise, though there have only been a few finds (of real ones) in the last few years...A certain dealer you know always has a few in stock....
