The most valuable card illustrated by Masahiko Ishii is Gardevoir ex δ (Dragon Frontiers) at $174, ahead of Kingdra ex δ ($125) and Torterra ($38).
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 Masahiko Ishii card is Gardevoir ex δ (Dragon Frontiers) at $174, followed by Kingdra ex δ (Dragon Frontiers) $125, Torterra (Diamond & Pearl) $38, Staraptor (Diamond & Pearl) $20, Floatzel (Diamond & Pearl) $3. Prices are TCGplayer market for raw copies (any condition) and refresh daily.
TickerMint tracks 5 Pokemon cards illustrated by Masahiko Ishii across 5 printings, with a combined market value of $360 counting each card once at its priciest printing.