Comment by Maxion

Lithography is AFAIK the most expensive part. If you wanna scale to larger wafers I'd guess you're talking hundreds of billions and at least a decade. And even then, what will your yield be? Surface area grows to the square of the diameter of a circle, and so will errors. The larger your wafer goes the lower your yield will go, especially if you're going to use the whole wafer in one final product.