The number of different types of screws is a pretty good indication of how many independently-designed subsystems are being stuck together. Despite the A7/A7R seeming like they were pushed out the door a bit quickly, it is impressive to see that Sony coordinated the design, engineering, and manufacturing processes so tightly.
It is worth noting, however, that Cicala’s conclusion that the A7R is cheaper to make than a DSLR is probably only half right. It looks like Sony invested the money up-front on design and engineering of new subsystems so production cost is low, whereas most DSLRs try to moderate costs by sticking-together existing subsystems that are cheap due to long-term volume production. The real difference is that this is why Sony gets to innovate without a huge cost penalty.
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.