Gengar #SWSH052 from SWSH Black Star Promos is a reverse holo promo card that currently sells for about $116 ungraded, with graded copies ranging from $88.76 at grade 7 to $3,002 at grade 10. A grade 10 copy sells for around $3,002, about 26× the $116 raw price, so high-grade copies are worth grading.