Cornerstone Mask Ogerpon ex #160 from Prismatic Evolutions is a holo illustration_rare card that currently sells for about $13.63 ungraded, with graded copies ranging from $12.00 at grade 7 to $99.99 at grade 10. TCGrader's AI has graded 3 copies of Cornerstone Mask Ogerpon ex (Prismatic Evolutions), averaging 9 overall. 100% scored 9 or higher, so clean copies are common and centering usually decides the top grades. A grade 10 copy sells for around $99.99, about 7.3× the $13.63 raw price, so high-grade copies are worth grading.