In music, the call "Shave and a Haircut" and the associated response "two bits" is a simple, 7-note musical couplet or riff popularly used at the end of a musical performance. It dates back to the late 1800's. "Two bits" is an archaism in the United States for 25 cents, a quarter. Historically, the Spanish "dollar" was often actually cut into 8 pieces and circulated that way. Each piece had the equivalent value of 12.5 cents and 2 would be a quarter of the dollar.

If the cost today is $25.00, then the increase in cost over the years is $24.75. So from 25 cents to 25 dollars is a 100 fold increase.

More Info: en.wikipedia.org