Dialga

Grading with PSA pays if your copy has better than a <1% chance of a 10.

6% of the 218 copies PSA has graded got a 10. People mostly send their cleanest copies, so a typical raw copy's odds are lower.

Raw (NM)

$40.40

TCGplayer

PSA 10

$2,848

7 sales

PSA 9

$130.48

13 sales

If it misses

$94.43

below 10, by PSA's grades