These don’t seem to pop up on ebay very often so it’s tough to say. There’s only 15 that got a 10 grade so pretty rare. One apparently sold on ebay recently for $500 and that seller has another one listed. That’s a pretty big gap between the 9 and 10 but given the pop it’s not too crazy.
Yeah, the difference is in the holofoil pattern. The gold stamp ones have the cosmo foil pattern while the brown stamp ones have the base set holo pattern(dont know whats that called, base set foil maybe??)
I’m the seller that has them up on ebay, I sold one for 425 USD around 1 hour after I listed them. Didn’t know people were willing to pay that much for them to be honest, was quite surprised myself.