Mewtwo-EX #BW45 from BW Black Star Promos is a holo promo card that currently sells for about $9.61 ungraded, with graded copies ranging from $18.50 at grade 7 to $300 at grade 10. A grade 10 copy sells for around $300, about 31× the $9.61 raw price, so high-grade copies are worth grading.