SWSH07: Evolving Skies Full Face Guard #231: PSA 9 vs PSA 10

The PSA 10 to PSA 9 spread on SWSH07: Evolving Skies Full Face Guard #231 is a wide gem-mint premium: $32, with PSA 10 copies trading at 3.1x a PSA 9. Based on a recent PSA 10 sale of $59.95 on May 15, 2026, the math leans toward holding the 9: expected value turns negative at conservative upgrade probabilities once the resub fee is in.

PSA 10

$47.14

Last sale $59.95 on May 15, 2026 UTC

PSA 9

$15.00

Last sale $15.00 on May 2, 2026 UTC

PSA 8

—

Limited recent sales tracked. Pull eBay sold comps before acting.

The Spread

The PSA 9 to PSA 10 spread on Full Face Guard #231 SWSH07: Evolving Skies.

$32

Dollar gap, PSA 9 to PSA 10

3.1x

PSA 10 sells for 3.1x a PSA 9

Three-Outcome EV Calculator

PSA 9 acquisition cost ($)

PSA resub cost ($)

Probability of each outcome (must total 100%)

PSA 10 (upgrade) 15%

PSA 9 (regrade) 70%

PSA 8 (downgrade) 15%

Defaults are conservative starting points. Adjust based on the specific slab. A borderline 9 with strong centering plays differently than a 9 with edge wear.

PSA 10 outcome (sale price minus resub minus acquisition) $0

PSA 9 outcome (regrade, no upgrade) $0

PSA 8 outcome (downgrade, slower sell, tied capital) $0

Expected Value

Math favors holding the 9

Where this card lands in the broader SWSH07: Evolving Skies picture: a non-holo with a $32 gap between PSA 9 and PSA 10. The PSA 9 to PSA 10 jump on WOTC-era cards reflects population scarcity at the top grade, not raw print run.

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