Mewtwo #14 from Wizards Black Star Promos is a promo card that currently sells for about $15.74 ungraded, with graded copies ranging from $35.00 at grade 7 to $2,006 at grade 10. TCGrader's AI has graded 8 copies of Mewtwo (Wizards Black Star Promos), averaging 7.5 overall. A grade 10 copy sells for around $2,006, about 127× the $15.74 raw price, so high-grade copies are worth grading.