It's very misguided to extrapolate in that way from the iPhone. After all, it's a
phone! That
is its primary function. It's just dandy that the iPhone can also act as a powerful information tool.
This thing, it's an information tool first and foremost. Also, professionals are willing to pay top dollar. Apple already makes lots of unlocked top-dollar hardware aimed at creative professionals.
But the real kicker -- Apple could sell almost the exact same hardware, with a few tweaks. Voila, a new product with even higher margins.