Really? And the $2000 includes power supply?!

So the hardware cost / hash is less than 40% of typical GPU rigs, if you bought damn cheap GPU at nearly $210, and only 1/5 the cost if you bought overpriced $400+ RX 480. Power is only 18% of GTX 1070 rigs with the same hash.

Sounds too good to be true. How are the high power efficiency and low cost achieved?