Only a very small premium so I keep it for myself it were mine, especially if you found it. It's a nice error and it shows one of the things that can happen to a coin at the Mint.
Do I see zinc in the lower one? split plating rather than die crack ?? can't really tell from the picture.
Not a die crack, imo. Doesn't look like what's normally called 'split copper plating', but it does look to be a plating issue. Not the normal 'bubbles' we see, but probably a similar cause.
"The end result was that most pieces are less than fully struck and display many die cracks, cud rim breaks and other technical flaws. Gems are available only due to the usual widespread saving of new coin types by the public for their novelty. Even those having high grades will usually exhibit some signs of die duress." NGC COIN EXPLORER
