It's that (once everything is set up) that will kill you. Now come up with $3 billion to build a 300mm-wafer fab...
Then hire a bunch of engineers and technicians to run the fab ... and another bunch of E&T to design the chip ... and another bunch of E&T to test the chips ... and hire all the folks necessary to keep your company running, get materials from where they are to where they need to be ...
It's really amazing that we can get CPUs for the dirt-cheap price of $100.
We're standing on the shoulders of giants.