Brother luvmysuper,Bearing in mind I'm talking current cost of vintage razors, not the inflation adjusted cost of them at the time they came out.
Some of the New and New Improved Gift sets were selling for up to 75 dollars. In 1930, 75 dollars is equal to about 1200 dollars in todays money.
Conversely, the 1940's Super Speed was selling for 1 dollar - that's about 15 bucks in todays inflation corrected money.
Respectfully, you may have gotten the prices of the Gillette New Improved razor tangled up during the typing. In 2012, I bought a beautiful triple-plated silver 1921 Gillette New Improved razor, including its silver blade bank and its black leatherette case. My notes about the purchase read thus: "It cost $5 in 1921, the equivalent of about $65 dollars in 2012."