Porygon #HGSS22 from HGSS Black Star Promos is a reverse holo promo card that currently sells for about $11.68 ungraded, with graded copies ranging from $15.50 at grade 7 to $200 at grade 10. A grade 10 copy sells for around $200, about 17× the $11.68 raw price, so high-grade copies are worth grading.