Goldspan Dragon #139 from Kaldheim is a foil mythic card that currently sells for about $22.71 ungraded, with graded copies ranging from $30.82 at grade 9 to $34.00 at grade 9.5. A grade 9.5 copy sells for around $34.00 vs $22.71 raw. That's a modest premium, so grading only pays off for near-perfect copies.