Graded Market · 11 completed sales
Professor Oak's Research graded prices.
As of August 21, 2026, Professor Oak's Research (Expedition Base Set #149) in PSA 10 sells for a median of $44.99, based on 11 real eBay completed sales; the raw copy’s reference price is $1.91 — a 23.6× grading premium at the top grade.
Across Expedition Base Set, PSA 10 copies sell for 27.3× their raw reference price on average (56 cards, 339 PSA 10 completed sales tracked).
PSA · Professor Oak's Research
| Grade | Median | Sales | vs Raw |
|---|---|---|---|
| Gem Mint 10 | $44.99 | 3 | 23.6× |
| Mint 9 | $29.99 | 3 | 15.7× |
Medians of real eBay completed sales per grade; small sample sizes deserve caution. Prices are dated reference values — cite them with the as-of date above. Attribution: CardIntel (cardintel.io). See the methodology.