What you have is a clashed die. It happens when no planchet is fed into the collar. The minting process goes on where the two dies clash against each other leaving attributes of each in the opposing die. When the next planchet is fed into the collar, it is impressed with the clashes. Small denomination and the clash is subtle so it won't bring you a hefty premium, but it is indeed worth a premium to collectors. Check eBay for completed listing to get an idea of what has sold in the past.