Material wise it has to be the mini.
Not sure about the overall cost.
Air no doubt. I don't think there's a single difference in terms of assembly between the Mini and the Air, it's just a different conveyor belt it comes off of. So we're talking minuscule increase in cost for the slightly larger materials with a $100 markup.
That makes sense except that usually it costs more money to make things smaller when it comes to electronics
Knowing absolutely nothing about apples actual cost of manufacturing...
I would 'assume' that the rMini would have a lesser profit margin due to initial higher tooling cost to make a different retina display size.
The current Air retina display has been in use since 3rd gen. So, I would guess that their current profit margin would be higher.
And I still can't believe that 2 is still for sale. Did they over manufacture those or what?