Because these are produced in extremely small quantities, they have become long-term grails for collectors seeking the pinnacle of One Piece rarity
This is how the database earns its keep over a vague Google search: you can stack constraints and arrive at the exact short list of cards youd consider
Name a Card and Search Hand, Graveyard and Library Then Exile It While these are probably better in regular formats and not singleton formats like Commander, they can still be useful
Theres the core spell, which takes up most of the card, and a subtype Adventure spell, located in the bottom left
You can read more about it here.
Card grading services are professional at it, and while how much it costs to get your card graded is a big discussion, for 100 of the most expensive cards that are worth hundreds or thousands of dollars, it makes sense and builds confidence and trust in your buyer