RKB> A 6x7 piece of silicon is _always_ going to be VERY expensive and rare. RKB> Moore's law does not apply here (nor even in FF 35mm sensors, IMHO)- RKB> these chips are just giants.
Just to add to what you wrote, Moore's law never applied to silicon chip size. All the chips are about same size the last 20 years or so. Including the newest Pentiums. The only thing it applies to is miniaturisation of the individual transistor "elements". ie pixels in CCD/CMOS chips. But you can't miniaturise them indefinitely because noise steps in. So unless the technology reaches entirely new level, bigger chips will always be much more expensive, as you said. Interestingly, the Mars Lander robot used a very old 8bit CPU for its main "brain", because, although physically same size as Pentiums, its transistors were much larger (because there were so few of them compared to modern CPUs). They used a slow chip because of cosmic rays, which didn't have much impact if they hit a large area transistor, but which could do much more errors if hitting smaller transistors. It's the same principe why small pixel CCDs are so noisy. Best regards, Frantisek Vlcek