Alolan Marowak-GX #SM187 from SM Black Star Promos is a reverse holo promo card that currently sells for about $10.47 ungraded, with graded copies ranging from $32.00 at grade 7 to $270 at grade 10. A grade 10 copy sells for around $270, about 26× the $10.47 raw price, so high-grade copies are worth grading.