If I recall, my old 1954 "Red Book" listed it at $12.50. A 1956 price list
from B. Max Mehl shows it at $40 in contrast to a 1937 price of $1.25. But
then in 1937 you could have bought lunch for five for $1.25.
In 1937 White Tower and White Castle hamburgers were a dime or 12 for
a dollar.
I worked in a drug store in 1940 and a banana split was12 cents
I do remember White Tower burgers still at ten for a dollar into the 1950's.
I think they just kept getting smaller. I could never work (for long) in a
drug store that sold banana splits for 12 cents. Couldn't stand the
torture.