Brock's Zubat #24 from Gym Heroes is a rare card that currently sells for about $8.33 ungraded, with graded copies ranging from $7.00 at grade 7 to $57.00 at grade 10. A grade 10 copy sells for around $57.00, about 6.8× the $8.33 raw price, so high-grade copies are worth grading.