Koraidon #91 from Scarlet & Violet Black Star Promos is a reverse holo promo card that currently sells for about $4.01 ungraded, with graded copies ranging from $16.22 at grade 9 to $46.71 at grade 10. A grade 10 copy sells for around $46.71, about 12× the $4.01 raw price, so high-grade copies are worth grading.