Championship Arena #28 from Nintendo Black Star Promos is a reverse holo promo card that currently sells for about $1,066 ungraded, with graded copies ranging from $1,664 at grade 7 to $5,750 at grade 10. A grade 10 copy sells for around $5,750, about 5.4× the $1,066 raw price, so high-grade copies are worth grading.