Magikarp #XY143 from XY Black Star Promos is a reverse holo promo card that currently sells for about $66.50 ungraded, with graded copies ranging from $55.00 at grade 7 to $800 at grade 10. A grade 10 copy sells for around $800, about 12× the $66.50 raw price, so high-grade copies are worth grading.