What makes it rare?
Have you ‘logged’ it on your collection page yet (please forgive the pun - couldn't resist 😁)? You'll soon see the rarity index below come down a few points from 100, perhaps to 97. That should be enough to demonstrate that this index isn't an indication of how rare a coin is, but how many of our members own one.
As for value, you'll need to find a willing buyer to find out exactly how much it's worth. Let us all know how you get on.
Hope you're not too disappointed.