It's worth $50.00 for sure. Seriously, it's a series 1928 A bill. The condition will lower the value. How many were printed, the signatures and a host of other things will determine the value. It's a neat item to have. Did you note that it's payable in Gold to the bearer on demand. That won't happen today.
I'd say the bill is worth right around $75-$80. If I were you I'd keep it. Maybe frame it to put at your desk or something? This note is a Gold Certificate so back in the day you could go to a bank and exchange this $50 bill for $50 worth of Gold. In 1928 1 ounce of Gold was $20.66 so you would have gotten 2.5 oz of gold in exchange for this note. Equivalent to $2854.5 today.
It's not a Gold Certificate, but a series 1928-A Federal Reserve Note. Less than a million printed for the St. Louis district. They're available in Unc and Gem, and I don't think there is a high demand for this series due to the popularity of the 1928 FRN's. It's 1928 equivalent, with the numerical seal, is scarcer with just over 600,000 notes printed and commands a much higher premium. Find the right buyer and I think Josh's estimate of $75 to $80 is accurate. I'm always on the hunt for 1928 and 1928-A $50 notes. I learned something new today: There were Gold Certificates printed for 1928-A and 1934, but were never released and ultimately destroyed. What a bummer.
