Just to have a rough aproximation what fraction of mobile phone turnover is due to components (including design, engineering, manufacturing and assembly).

http://www.fairphone.com/wp-content/uploads/2013/09/FAIRPHONE_CostBreakdown_150dpi_130913.jpg

And to have a bill of material for a iphone 5 ...

https://technology.ihs.com/410378/iphone-5-carries-199-bom-virtual-teardown-reveals

... saying that its processor is a 44 $ fraction of 199 $ manufacturing costs (e.g. for iphone 5 16GB), beeing 22% of BOM (=44/199) or 6,7% (=44/649) of turnover.

Make of it what you want. Some might like this study trip. Sorry for the slight offtopic :)