Franklin Half dollars are common coins, complete sets (35 coins) are not hard to find. Because of this, and the high price of silver, circulated coins are valued slightly above the silver content of the coin about $11.00 each. Only a set of Mint State coins would have a higher premium. Also for this series no coins with a "S' mintmark were struck after 1954.
It's worth at least $11 for its silver content, and a bit more if it's in uncirculated condition.