Quaquaval ex #84 from Scarlet & Violet Black Star Promos is a reverse holo promo card that currently sells for about $2.79 ungraded, with graded copies ranging from $9.99 at grade 9 to $35.00 at grade 10. A grade 10 copy sells for around $35.00, about 13× the $2.79 raw price, so high-grade copies are worth grading.