Hendy’s Law (pixels per dollar)

http://en.wikipedia.org/wiki/Moore%27s_law#Other_formulations_and_similar_laws

Pixels per dollar. Similarly, Barry Hendy of Kodak Australia has plotted the "pixels per dollar" as a basic measure of value for a digital camera, demonstrating the historical linearity (on a log scale) of this market and the opportunity to predict the future trend of digital camera price, LCD and LED screens and resolution.