TCGrader's AI has graded 16 copies of Mewtwo & Mew-GX (SM Black Star Promos), averaging 8 overall. Only 19% scored 9 or higher, so genuinely mint copies of this card are scarce. A grade 10 copy sells for around $1,925, about 6.1× the $315 raw price, so high-grade copies are worth grading.