Zekrom-GX #SM138 from SM Black Star Promos is a reverse holo promo card that currently sells for about $14.84 ungraded, with graded copies ranging from $17.50 at grade 7 to $31.00 at grade 10. A grade 10 copy sells for around $31.00, about 2.1× the $14.84 raw price, so high-grade copies are worth grading.