Blastoise-GX #SM189 from SM Black Star Promos is a reverse holo promo card that currently sells for about $18.00 ungraded, with graded copies ranging from $19.84 at grade 7 to $380 at grade 10. A grade 10 copy sells for around $380, about 21× the $18.00 raw price, so high-grade copies are worth grading.