Not to dispute, could you post a link because I would love to see how he expressed this, and work out how I feel about it. At one level it's a truism, if you w

Not to dispute, could you post a link because I would love to see how he expressed this, and work out how I feel about it. At one level it's a truism, if you wind up with price the main constraint on something, if it is substitutable you will go to a cheaper substitute, when price exceeds some threshold but that threshold is variant to circumstance, and the consequences of substitution also come to play.