Groudon-EX #XY42 from XY Black Star Promos is a reverse holo promo card that currently sells for about $4.80 ungraded, with graded copies ranging from $1.25 at grade 7 to $222 at grade 10. A grade 10 copy sells for around $222, about 46× the $4.80 raw price, so high-grade copies are worth grading.