Grosch’s law

Before the advent of micro processors around about the 80’s Herb Grosch noted that the performance of a computer was roughly proportional to the square of its cost. This was in part a technical consequences but also a marketing strategy.

Grosch, H. A.High speed arithmetic: the digital computer as a research tool, J. Opt. Soc.
Am. 43, 4 (April 1953).