Not paticularly rare, the Roman Republic types with the Goddess "ROMA" at the front and a god/goddess (in this case, VICTORY) driving a BIGA on the reverse are usually plentiful at auctions and dealers, but still interesting and a prime example of a Roman Republic denarius. It is hard to make out the inscriptions on the reverse, so it will be difficult pinpointing the Moneyer who issued this type. All I could make out is the letters C.M at the end, the first name could be Cippius or something. The other word at the very bottom of the reverse is just the name ROMA (ROME), referring to the mother city where the coin was minted.
Probably Crawford 203/1a. This is my example - http://www.tantaluscoins.com/coins/110478.php ATB, Aidan.