Celebi #XY187 from XY Black Star Promos is a reverse holo promo card that currently sells for about $9.47 ungraded, with graded copies ranging from $15.01 at grade 7 to $95.00 at grade 10. A grade 10 copy sells for around $95.00, about 10× the $9.47 raw price, so high-grade copies are worth grading.