Porygon-Z-GX #SM216 from SM Black Star Promos is a reverse holo promo card that currently sells for about $13.11 ungraded, with graded copies ranging from $7.50 at grade 7 to $139 at grade 10. A grade 10 copy sells for around $139, about 11× the $13.11 raw price, so high-grade copies are worth grading.