As I have mentioned in the past, my discussions with people at Microchip and Motorola have conceded that with modern process technology the cost of the silicon is insignificant compared to the cost of packaging and testing. As a result you get to about $1/chip in singles as the low price cut-off but you can put an 8 bit, 16 bit, or 32 bit processor in there and it doesn't change the cost. It can cost more if you add a lot more FLASH or RAM. That takes up silicon real estate and is longer to test so it can reach the point where the dice is once again a meaningful contributor to the cost.
I guess that makes sense, and it's not a particularly new phenomenon. The MOS 6507 (used in the Atari 2600) was mostly the same silicon as the 6502 (as used in Apple II and many other places), but cheaper because it was in a smaller package.
As I have mentioned in the past, my discussions with people at Microchip and Motorola have conceded that with modern process technology the cost of the silicon is insignificant compared to the cost of packaging and testing. As a result you get to about $1/chip in singles as the low price cut-off but you can put an 8 bit, 16 bit, or 32 bit processor in there and it doesn't change the cost. It can cost more if you add a lot more FLASH or RAM. That takes up silicon real estate and is longer to test so it can reach the point where the dice is once again a meaningful contributor to the cost.