Don't know the odds, but I think only 10 made of each player and given non collectors probably ate the chips and played frisbee with them, these are one of the few cards you could actually use the word....RARE to describe.
Like everyone else I'm in the queue if any St George ones come up for sale....
You're right about kids not taking much care of them. I need a Buderus 2006 Signature to complete my Knights set ... after exhaustive Internet searching, I actually found a guy on a forum that mentioned having one ... contacted him by email ... he said he lost it when he moved house. ;(