The LLC that included Intel funded our one project (EUVL) with 100s of millions of dollars- they were quite serious about it (The laser I ran was just one part of the project and I was told it cost 20 million dollars)... Intel has announced it is committing to EUVL technology...

I can't say if it is a good thing to do business wise, but I can say the industry IS serious about doing it... (While your simple scaling of fab plant cost is bogus at best, I will admit it will be VERY costly- EUVL tech (At least when I left the project) is NOT simple or cheap- It was pushing the very edge of what was possible 3 years ago.

We were focussing a 1.5 kW laser into a jet of liquid Xenon to create a plasma that radiated in the Extreme Ultraviolet (13.6 nm) - the EUV light was collected with cutting edge (shaped with precision measured in atomic layers) optics and used to make features on silicon wafers.

That was the only laser I have worked on that really terrified me (It was my first job out of school)- when I first aligned it along the beam train into the vacuum chamber one of my alignment tools was a flashlight to see the smoke from stray light hitting stuff it shouldnt... When the coating on a mirror failed it sounded like a 10000 pound bumblebee as the laser drilled through the glass and whatever was behind the mirror.

The laser based approach was just one way the companies were looking at to generate the EUV light, but I think it is the approach that eventually won out.