Yveltal-EX #XY08 from XY Black Star Promos is a reverse holo promo card that currently sells for about $4.45 ungraded, with graded copies ranging from $14.00 at grade 7 to $735 at grade 10. A grade 10 copy sells for around $735, about 165× the $4.45 raw price, so high-grade copies are worth grading.