Zariel, Archduke of Avernus #285 from Adventures in the Forgotten Realms is a full art foil / borderless mythic card that currently sells for about $4.56 ungraded and around $39.95 at grade 10. A grade 10 copy sells for around $39.95, about 8.8× the $4.56 raw price, so high-grade copies are worth grading.