Professor Oak’s New Theory

HeartGold SoulSilver · 101/123 ·Uncommon

Illustration: Ken Sugimori →

Market price

$3.15

Price history · RAW

2025-12-09 · $0.95 $8.22 · 2026-07-20

Cross-market · RAW median per marketplace

Spread vs. cheapest market — before shipping/duty/fees

ebay.es	n=13	$2.10	+115%
ebay.de	n=4	$1.73	+77%
ebay.com	n=9	$0.98	—

Price per print

🇬🇧 Normal · EN n=14 $3.15

🇩🇪 Normal · DE n=1 $1.39

How is this value calculated?

Ladder estimate · English · ~$3.15 gruen

Evidence path	Sales	Age	Value vᵢ	Weight gᵢ
eigene LP-Verkäufe ÷ 0.7569	4	3 mo	$3.15	2.59

value = exp( Σ gᵢ·ln vᵢ ⁄ Σ gᵢ ) = $3.15 · Σ g = 2.59

Measured error for this era×language (backtest): ±19 %

Ladder estimate · Deutsch · ~$1.39 rot

Evidence path	Sales	Age	Value vᵢ	Weight gᵢ
en LP ÷ 0.7569 × 0.4414	4	3 mo	$1.39	0.97

value = exp( Σ gᵢ·ln vᵢ ⁄ Σ gᵢ ) = $1.39 · Σ g = 0.97

Measured error for this era×language (backtest): ±27 %

Gate not green — shown only here, never as the price.

PSA Population EN Σ 33

PSA 10

3 9%

PSA 9

16 48%

PSA 8

6 18%

PSA ≤7

8 24%

PSA + CGC · as of 2026-09-28

Recent sales · 27

2026-07-20	EN	RAW UNKNOWN	PROFESSOR OAK'S NEW THEORY 101/123 HEARTGOLD & SOULSILVER Un · eBay	$3.28
2026-07-18	EN	RAW NM	Professor Oak's New Theory 101/123 Uncommon HeartGold & Soul · eBay	$2.33
2026-07-14	EN	RAW UNKNOWN	Pokemon Karte Heartgold Soulsilver Nr. 101/123 Professor Oak · eBay	$1.12
2026-07-08	EN	RAW UNKNOWN	Professor Oak's New Theory HeartGold SoulSilver 101/123 Poke · eBay	$1.95
2026-07-05	EN	RAW UNKNOWN	Professor Oak’s New Theory 101/123 Uncommon Heart Gold Soul · eBay	$1.56
2026-07-01	EN	RAW UNKNOWN	Pokemon - Professor Oak's New Theory - 101/123 - Uncommon - · eBay	$1.02
2026-06-21	EN	RAW UNKNOWN	Pokemon Professor Oak's New Theory Holofoil Card 101/123 Wor · eBay	$0.98
2026-06-20	EN	RAW LP	Professor Oak's New Theory 101/123 Barajas Campeonato Mundia · eBay	$2.33
2026-06-20	EN	RAW UNKNOWN	Professor Oak's New Theory HeartGold SoulSilver Uncommon 101 · eBay	$3.51
2026-06-19	EN	RAW HP	PROFESSOR OAK'S NEW THEORY - 101/123 - HeartGold SoulSilver · eBay	$1.76
2026-06-19	EN	RAW UNKNOWN	Professor Oak's New Theory 101/123 \| HGSS \| Pokemon TCG \| In · eBay	$1.75
2026-06-17	EN	RAW UNKNOWN	Tarjeta Pokémon HeartGold y SoulSilver Professor Oak's New T · eBay	$1.75
2026-06-17	EN	RAW MP	Professor Oak's New Theory 101/123 Uncommon HeartGold & Soul · eBay	$0.95
2026-06-16	EN	RAW MP	Pokemon Professor Oak’s New Theory 101/123 Heartgold & Souls	$2.23
2026-06-13	DE	RAW UNKNOWN	Professor Eichs neue Theorie 101/123 Heartgold & Soulsilver	$1.12
2026-06-12	EN	RAW DMG	Professor Oak's New Theory 101/123 Poco Común HeartGold y So	$1.86
2026-06-12	EN	RAW MP	Professor Oak's New Theory 101/123 Poco Común HeartGold y So	$2.10
2026-06-12	EN	RAW MP	Professor Oak's New Theory 101/123 Uncommon HeartGold & Soul	$0.97
2026-05-30	EN	RAW UNKNOWN	Pokemon TCG HeartGold SoulSilver Professor Oak's New Theory	$1.65
2026-05-18	EN	RAW LP	Pokemon TCG HeartGold SoulSilver Professor Oak's New Theory	$0.97

Frequently asked questions

What will I get for Professor Oak’s New Theory HeartGold SoulSilver 101/123 if I want to sell quickly?

Half of all sales fell between $1.12 and $2.33, with a median of $1.75. Selling fast lands you nearer the lower end; with patience, good photos and a complete title the upper end is achievable.

Below which price is an offer for Professor Oak’s New Theory HeartGold SoulSilver 101/123 unrealistic?

The cheapest genuine sales were around $0.97. Offers well below $0.58 are typically fakes, mislabelled cards or a different variant — ask for photos of all four borders and a close-up of the surface.

How does lastsold determine the market value?

lastsold uses only real sales — eBay plus auction houses like Goldin & Fanatics — recent sales count more (recency weighting), outliers and fakes are removed. It's not an estimate but actual sold prices, separated by condition, language and grading.