The difference between men and boys
Is the price of their toys.

Malcolm Forbes (1919-1990) American billionaire
The Sayings of Chairman Malcolm, “Simple Truths” (1978)

Also attributed to Liberace, J. T. Russell, Joyce Brothers, Mark Twain, Doris Rowland, and Dorothy Parker. The phrase can be found in this form in Millard Dale Baughman, Educator's Handbook of Stories, Quotes and Humor (1963), and in 1964 Senate testimony.

For a likely predecessor, see Franklin.