One point of education: since your list includes costs that can be arbitralily set by Apple (eg, cross-subsidies), no one is going to educate you on what the br

One point of education: since your list includes costs that can be arbitralily set by Apple (eg, cross-subsidies), no one is going to educate you on what the break-point is (and also it requires too intimate knowledge of financials of a very secretive company)