The 1868 Proof Three Cent Nickel comes from a mintage of just 600 coins, most of which still exist. Common up to the gem level. PR65 and PR66 are scarce and all grades finer are rare. Examples with eye catching color and strong strikes are out there if you're up for the hunt. There is a small, gradual premium for cameos with an increase in rarity and desirability for deep cameos.