I doubt that cost is the concern. Both Apple and Intel are big players, they can find a fair price between them, and Apple always had the threat of switching to ARM to get better prices.
I'm pretty sure this move is for power consumption and maybe so all Apple products are on the same architecture.
A13X cost $30, compared to cheapest Intel used in MacBook Air cost $200+. I think it is quite a difference. That means consumer are paying $300+ for x86 compatibility.
> A13X cost $30, compared to cheapest Intel used in MacBook Air cost $200+.
You aren't comparing costs fairly here. A13X costs $30 each + $XXX million to develop. With Intel the development costs are part of the SKU. If Apple launches a series of desktop CPUs, the cost to develop those chips is going to be substantial. Some of that cost will be in common with the iPad/ iPhone, but a good chunk will be unique to their new CPUs. Since Apple ships far fewer Macs than iPhones, the development cost/ unit will be significantly higher.
Apple designs their own chips. They have a single fixed cost for the design work which gets amortized by the massive volume of device sales. The only variable cost is the cost of third party fabrication. AMD can’t compete with that.
I'm pretty sure this move is for power consumption and maybe so all Apple products are on the same architecture.