I know one thing.
Many years ago on Rec Games Pinball. Someone restored a Rocky pin. New playfield, plastics, everything. He was asking an exorbitant price for it. I don't know if he got it or not.
Ever since then that game's asking price went through the roof. People used it as a price guide.
Until then, it was a $500 pin.
No idea on rarity or great game/fun factor.
LTG : )