12 cycles of Moore's Law puts that 3.56 million figure at $869.14. Unlocked cost on the Apple store: $749
3,560,000 * 0.5 ^ 12 ≈ 869.143,560,000 * 2 ^ -12 ≈ 869.14
Based on: 1/2 ^ 12 = 2 ^ -12
Yes, I've noticed that in other contexts. It's too bad because it makes the representation less clear, more complex than necessary. I first became aware of this when I tried to say that gravitational force declines as r^-2, to numerous protests.
Oh, well -- a tempest in a teapot, as they say.
The effect of Moore's "law" is that processing power doubles approximately every 2 years, while the cost halves.
If 1 "unit" of processing currently costs $1; in 2 years time, 2 units will cost $1. Or that 1 unit costs 0.50.