A Tony Gwynn single signed Baseball is worth about $75.-$100. Value is based on average prices of recently closed auctions. Prices may vary based on condition, and the type of authenticity that accompanies the signature. Signatures that have not been properly authenticated could sell at half the market value or less. Add for inscriptions. Collectors will pay more for inscriptions like "3141" and pay less for personal inscriptions like "Good Luck Chuck" In a recent auction a Tony Gwynn single signed baseball sold for $83.65
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