Doubling Season #283 from Commander Masters is a mythic card that currently sells for about $29.99 ungraded, with graded copies ranging from $26.50 at grade 9 to $29.00 at grade 9.5. A grade 9.5 copy sells for around $29.00 vs $29.99 raw. That's a modest premium, so grading only pays off for near-perfect copies.