It takes quite a bit of computing power to set the price of something like an iphone.You're missing the point.
It doesn't take a genius or supercomputer to set the initial price of one good or a small number of related goods, and changing it as demand rises and falls; kids working at trading stalls have been doing that for centuries. What I'm talking about is the *fixing* by a civil servant of the prices of *all* goods and services. No one or no thing can make such judgements or predictions.
That's why a 'command economy' will always fail.