Grimer

Grading with PSA pays if your copy has better than a 26% chance of a 10.

22% of the 675 copies PSA has graded got a 10. People mostly send their cleanest copies, so a typical raw copy's odds are lower.

Raw (NM)

$2.73

TCGplayer

PSA 10

$231.25

30 sales

PSA 9

$33.50

59 sales

If it misses

$31.16

below 10, by PSA's grades