Compare Jerry Koosman values across different grades. See whether grading is worth it based on current prices and PSA gem rates.
Price by Grade
| Grade | Guardian Estimate | Premium vs Raw |
|---|
| Raw / Ungraded | $2.70 | — |
| PSA 8 | $16.28 | +503% |
| PSA 9 | $36.14 | +1239% |
| PSA 10 Gem Mint | $310.98 | +11418% |
Frequently Asked Questions
Is Jerry Koosman worth grading? A PSA 10 Jerry Koosman is worth $310.98 vs $2.70 raw — a 11418% premium.
What is Jerry Koosman PSA 10 worth? $310.98 as of September 2026.