The Common Law of Business Balance is a meditation on price attributed to John Ruskin. It reads as follows:
It's unwise to pay too much, but it's worse to pay too little. When you pay too much, you lose a little money -- that is all. When you pay too little, you sometimes lose everything, because the thing you bought was incapable of doing the thing it was bought to do. The common law of business balance prohibits paying a little and getting a lot -- it can't be done. If you deal with the lowest bidder, it is well to add something for the risk you run, and if you do that you will have enough to pay for something better.
This is a classic quote on the possible folly of automatically choosing low cost as the best way to make a purchase decision. It appeals to those who believe, or who want to persuade others to believe, that price is a possible indicator of quality.