Greninja ex #148 from 30th Celebration is a illustration_rare card that currently sells for about $19.33 ungraded, with graded copies ranging from $17.50 at grade 9 to $17.50 at grade 10. TCGrader's AI has graded 3 copies of Greninja ex (30th Celebration), averaging 9.3 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 $17.50 vs $19.33 raw. That's a modest premium, so grading only pays off for near-perfect copies.