@GR!FF!N: I am only interested in flyaway cost as that will be the price that Pakistan will pay China for each J-31. Other costs will be budgeted separately like weapons, infrastructure and training.
The US arms manufacturers even profit from selling to the US government and make even more money per plane when it sells overseas.
Chinese will be able to build their plane cheaper and will sell at cost price to their number one ally Pakistan. 75 million dollars each, at today's prices, is a reasonable estimate of how much Pakistan will be charged by China for each J-31.
I expect Pakistan to buy between 100-150 J-31s, dependent on how their economy performs over the next 1-2 decades.