Wally's Compassion #186 from Mega Evolution is a holo illustration_rare card that currently sells for about $19.02 ungraded, with graded copies ranging from $10.49 at grade 7 to $35.00 at grade 10. A grade 10 copy sells for around $35.00 vs $19.02 raw. That's a modest premium, so grading only pays off for near-perfect copies.