100 times difficulty ~ 100,000,000 GH/s ~ 1,000,000,000 USD investments in mining gear
Who's gonna pay that?
You assumed prices of $10 per Ghash/s. It is well-known current ASIC vendors have insane margins on the raw silicon. As a matter of fact, Cointerra is already selling pre-orders $3 per Ghash/s. Watch the price drop to $1 or less per Ghash/s over the next 12 months. Therefore a $100 million investment in mining hardware is all you need for the network to grow to 100 Phash/s. This will happen by September 2014. Watch.
One year later... It is now September 2014, and the network has grown from 1.0 Phash/s to 250 Phash/s: I was right.
In fact we crossed 100 Phash/s in June 2014, so my estimation of when we would grow by 100x was correct with an error margin of ±90 days.
(Man, it has been a while since I logged on bitcointalk.)
You're right and I'm still amazed. My assumption of $10 per Ghash/s was indeed way off and then there's still a lot of money invested in the mining rush.