Champions Festival #XY27 from XY Black Star Promos is a reverse holo promo card that currently sells for about $1,600 ungraded, with graded copies ranging from $276 at grade 9 to $304 at grade 9.5. A grade 9.5 copy sells for around $304 vs $1,600 raw. That's a modest premium, so grading only pays off for near-perfect copies.