A Alex Rodriguez Ivan Rodriguez Duel Signed Bat is worth between $475.-$700. The most preferred bat for a signature is a bat closest to the size, and model the player used. The better the quality of the bat the higher collectors value it will have. 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.