As of 2014, the standard 1934 $50 bill is still in circulation, quite common and only worth face value. When found in perfect condition, these green seal bills do carry a slight premium.
According to Old Currency, LLC., variations of the bill bearing a star symbol at the end of the serial number may be valued up to $150. Additionally, early issues with at least five zeros at the beginning of the number may demand a slight premium, and those starting with six or seven zeros certainly carry a tag above face worth. Their exact value, however, is ultimately dependent on their condition and the demand of the collector seeking the bill.