Rillaboom #SWSH006 from SWSH Black Star Promos is a reverse holo promo card that currently sells for about $7.67 ungraded, with graded copies ranging from $29.99 at grade 9 to $39.99 at grade 10. A grade 10 copy sells for around $39.99, about 5.2× the $7.67 raw price, so high-grade copies are worth grading.