Trevenant #XY94 from XY Black Star Promos is a reverse holo promo card that currently sells for about $4.19 ungraded, with graded copies ranging from $28.04 at grade 9 to $67.85 at grade 10. A grade 10 copy sells for around $67.85, about 16× the $4.19 raw price, so high-grade copies are worth grading.