Yveltal #205 from Paradox Rift is a illustration_rare card that currently sells for about $14.38 ungraded, with graded copies ranging from $15.75 at grade 7 to $23.32 at grade 10. A grade 10 copy sells for around $23.32 vs $14.38 raw. That's a modest premium, so grading only pays off for near-perfect copies.