Though obviously never gaining traction in the vending machine business nor with the US mint—beverage distributors working out other forms of price-control and serving size, see previously, either through smaller portions or eating the margins to reduce competition, president of Squirt soda (see previously), one Edward Welsh Mehren, made a modest proposal in the late 1940s to introduce fractional coinage, in between the established US denominations of the nickel, dime and quarter (2½¢, etc) to provide some relief for consumers facing both the prospects of inflation and shrinkflation.
Even with the benefit of the penny, Mehren argued that prices were raised in five-cent increments—particularly for the coin-op business—when we more conservative margins would have worked for the companies to the benefit of consumers. Despite the lack of takers, Mehren continued his crusade well into the 1970s, advocating a two-and-a-half dollar bill, claiming that it was more efficient and made more economic sense to print a half-five dollar bills as the unpopular and considered unlucky to receive back in change Jefferson two-dollar had recently been discontinued in 1966—only to be reintroduced into circulation with a new design for the US bicentennial on the anniversary of the third American president’s birthday 13 April, 1743 (Old Style, 2 April). More from Weird Universe at the links above.