Thanks for your reply, I definitely see what you mean with other pricing schemes and how there is pretty wide latitude for what type of price discrimination is justifiable.

I mostly just find it silly that at no point does anyone seem to address the elephant in the room that the only way to access some hundreds of millions of users is through Apple, and that almost certainly influences the fee in a way that can't be really be explained by the value of the IP.

Does the argument require us to believe the fee would still be 30% if iPhone had practically zero users? Or is that legally irrelevant assuming that they aren't found a monopoly?