5 cents - Way before my time. White Castle hasn’t been a nickel since the 1930’s. My father, who is 90, remembers them being a nickel. They slowly increased by pennies thru the 1930’s & the 1940’s until they hit a dime & stayed at dime for a few yrs. In 1950, they went to 12 cents & stayed at 12 cents into the 1960’s.
Krystals were a nickel in the 60s, but it was the South, so they were cheaper.............