Those numbers seem way off. For example, Bitfury chips get around 2GH/s and they probably get ~4k dies out of a single wafer. Your cost for a fully processed wafer is also low, though not enough to even out with being possibly 20x on the number of chips.
Cost should be a lot lower than $2/GH/s at the board level to have chance of being competitive though. Cointerra is selling May delivery units in a chassis with cooling, controller and power supplies for $3/GH/s, and that's including markup to cover overhead. Cost for a 55nm product with chips shipping even in Q2 will have to be way below $1GH/s at the board level to be sensible.