Base Set Impostor Professor Oak 73/102: PSA 9 vs PSA 10
Base Set Impostor Professor Oak 73/102 shows an unusually wide gem-mint premium between PSA 9 and PSA 10: a $350 dollar gap, with the gem mint multiplier at 8x. Based on the last tracked PSA 10 sale of $400.00 on May 5, 2026, the crack-and-resub math favors the resub: expected value is positive even at a conservative 15% upgrade probability.
PSA 10
$400.00
Last sale $400.00 on
PSA 9
$50.00
Last sale $50.00 on
PSA 8
$28.00
Last sale $16.00 on
The Spread
The PSA 9 to PSA 10 spread on Impostor Professor Oak 73/102 (Base Set).
$350
Dollar gap, PSA 9 to PSA 10
8x
PSA 10 sells for 8x a PSA 9
Three-Outcome EV Calculator
15%
70%
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
$0
Math favors holding the 9
Where this card lands in the broader Base Set picture: a WOTC-era card carrying a $350 gap between PSA 9 and PSA 10, an 8x multiple on the PSA 9 price.
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