Delphox-EX #XY19 from XY Black Star Promos is a reverse holo promo card that currently sells for about $4.38 ungraded, with graded copies ranging from $11.75 at grade 7 to $400 at grade 10. A grade 10 copy sells for around $400, about 91× the $4.38 raw price, so high-grade copies are worth grading.