Gyarados-EX #XY106 from XY Black Star Promos is a reverse holo promo card that currently sells for about $13.87 ungraded, with graded copies ranging from $24.95 at grade 7 to $400 at grade 10. A grade 10 copy sells for around $400, about 29× the $13.87 raw price, so high-grade copies are worth grading.