The profit maximizing price after a 30% cut `q(price) * (price - 30%price)` is not the same as the profit maximizing price without that cut `q(price) price`.
As long as the demand curve is downward sloping, there will be some pass through of Apple's cut to customers, though the fraction that is passed through will depend on price elasticity.
As long as the demand curve is downward sloping, there will be some pass through of Apple's cut to customers, though the fraction that is passed through will depend on price elasticity.