Pffff... That's all incorrect.
An KnC-miner of 550 Gh/s costs about 6000 USD, and uses 650 Watt and currently makes 0.3 BTC per day.
Current network is 7,300,000 Ghs
Say this network is built out of KnC-miners then: 7,300,000 / 550 gives a total of 13,272 machines.
Using: 13,722 x 0.650...