Believe it or not, building rockets the way SpaceX does it, is in fact quite cheap. To get even 3 or 4 semi conductor fabrication plants up and running with 22nm or smaller node equipment would cost 10-20 billion USD. Which is vastly more investment than SpaceX has had (1 billion USD in total from its founding till 2012).
Not to mention the fact that the x86 license, which was historically given to AMD by Intel back when they were doing business with IBM for their newly created pcs (IBM demanded that there be at least 2 sources for the cpus), cannot be transferred from AMD and without it you cannot legally build a x86 cpu. Without that you're dead in the water.
Seriously the only competition that Intel have is AMD and they are struggling to survive. At least in periods of poor growth Intel can sell spare capacity at its world class fab plants (only company to have produced anything at the 14nm node). All AMD can do is cut costs (reduce R&D expenditure as mentioned before and/or lay off workers).