The most valuable card illustrated by OOYAMA is Magikarp & Wailord GX (Team Up) at $882, ahead of Moltres ($158) and Moltres ($55).
Value counts each card once at its highest-priced printing. The homepage leaderboard additionally requires a priced rarity cohort, so its totals run slightly leaner.
By TCGplayer market price, the most valuable OOYAMA card is Magikarp & Wailord GX (Team Up) at $882, followed by Moltres (XY Black Star Promos) $158, Moltres (XY Black Star Promos) $55, Beartic (Black Bolt) $12, Moltres (Fates Collide) $10. Prices are TCGplayer market for raw copies (any condition) and refresh daily.
TickerMint tracks 27 Pokemon cards illustrated by OOYAMA across 32 printings, with a combined market value of $1,098 counting each card once at its priciest printing.