Mew #8 from Wizards Black Star Promos is a promo card that currently sells for about $6.37 ungraded, with graded copies ranging from $23.52 at grade 7 to $375 at grade 10. TCGrader's AI has graded 12 copies of Mew (Wizards Black Star Promos), averaging 7.7 overall. A grade 10 copy sells for around $375, about 59× the $6.37 raw price, so high-grade copies are worth grading.