"Multiplicity ought not to be posited without necessity."
— Occam's Razor
The Common Law of Business Balance
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 cannot 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.
(Also sometimes appended to Ruskin's "Common Law of Business Practice," but doubtfully attributed):
"There is hardly anything in the world that some men cannot make a little worse and sell a little cheaper, and the people who consider price only, are this man's lawful prey."