The materials price isn't indicative of cost unless you know what assembly, shipping, replacements, 3rd party retail margins, R&D etc costs. Given Apple have designed their own chips since the A5 (with the A4 optimised by Intrinsity and Samsung, the former acquired by Apple) and their own GPUs since 2017 I'd say the R&D cost isn't trivial. Unlike manufacturers like Samsung etc, they make their own OS top to toe.
I think it's more useful to look at their financials as the iPhone is their highest grossing product, with guidance of a ~35-40% margin.
Tim Cook says he's never read a bill of materials that was anywhere close to accurate. I believe it- the last time I got an iPhone replaced, I asked what they were doing with the old unit and the person said they were probably going to reuse the touch id sensor since that was one of the most valuable parts.
The Touch ID sensor value in the second hand market is not reflective of the cost to Apple... it’s expensive because there are no third party replacements, so the supply is restricted to parts taken from broken phones.
Besides even other costs like r&d, marketing, and the retail margin, buyers are getting more than hardware - how much is the cost of OS development and the included apps?
That is why I mention Patents, and R&D likely to be the most expensive expense here. When you divide those Marketing, Operation and whatever cost over 300M unit / year. The number will be rather small.
I see the iPhone 7 cost of materials is $237. No wonder Apple makes so much money!