Mega Gengar ex #56 from Phantasmal Flames is a reverse holo rare card that currently sells for about $2.91 ungraded, with graded copies ranging from $13.50 at grade 7 to $99.99 at grade 10. A grade 10 copy sells for around $99.99, about 34× the $2.91 raw price, so high-grade copies are worth grading.