This underpins how astronomically profitable Apple must be, to have this degree of cost increase in an unsubstitutable input.<p>You would think at some point Apple would take a position in TSMC or replicate, internalising the profit from others is the Apple way, as wolfson (uk) found out, and in due course arm. TSMC seems to be resilient in the face of Apple's usual path here.<p>The article says they're believed to be the only customer who gets a per chip price, not a wafer price with yield guarantees. So no dud chips in iphone/ipad/macbook hands!