Professor Oak's New Theory
HeartGold & SoulSilver · 101/123 · Non Holo
Ungraded Market Price
£0.76
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Median of last 15 UK eBay sales
Updated 27 Aug 2026
Median of last 15 UK eBay sales
Updated 27 Aug 2026
Near Mint 🔒
£***.**
Lightly Played 🔒
£***.**
Mod. Played 🔒
£***.**
Heavily Played 🔒
£***.**
Ungraded
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Recent UK eBay Listings
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Pokemon Card TCG: Professor Oak's New Theory 101/123 - HeartGold & SoulSilver NM
Sold 10 Jun 2026
£0.30
View on eBay →
Pokemon TCG Professor Oak's New Theory 101/123 HGSS LP - MP Condition
Sold 30 Apr 2026
£0.79
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Pokémon TCG Professor Oaks New Theory Heartgold Soulsilver 101/123 Regular LP.
Sold 26 Mar 2026
£0.73
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Pokémon TCG Professor Oaks New Theory Heartgold Soulsilver 101/123 Regular MP.
Sold 21 Mar 2026
£0.63
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Professor Oak's New Theory 101/123 HeartGold SoulSilver Uncommon Pokemon MP+
Sold 02 Mar 2026
£1.15
View on eBay →
Professor Oak's New Theory 101/123 Heart Gold & Soul Silver Pokemon Card
Sold 29 Dec 2025
£1.38
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Pokémon TCG Professor Oaks New Theory Heartgold Soulsilver 101/123 Regular MP.
Sold 18 Nov 2025
£0.63
View on eBay →
Professor Oak's New Theory 101/123 HGSS Pokemon Card NM
Sold 14 Oct 2025
£0.92
View on eBay →
+ hundreds more sales available in the ValuDex app
Card Details
You can play only one Supporter card each turn. When you play this card, put it next to your Active Pokémon. When your turn ends, discard this card.
Shuffle your hand into your deck. Then, draw 6 cards.
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UK marketplace data. Zero currency conversions. Condition-true pricing.
A UK-focused Pokémon card pricing app that shows what cards sell for inc. Best Offer, filters out fake or incorrect listings, tracks your collection with a real-time portfolio, and helps you quickly see true condition-based valuations before you buy or sell.