Swampert-EX #XY55 from XY Black Star Promos is a reverse holo promo card that currently sells for about $5.36 ungraded, with graded copies ranging from $25.00 at grade 7 to $250 at grade 10. A grade 10 copy sells for around $250, about 47× the $5.36 raw price, so high-grade copies are worth grading.