As to calculation of damages. I would point out that it would be impossible to calculate accurately. Since we would have been dealing with vastly different difficulty numbers if BFL had actually delivered last year. Since they didn't I don't see how you could reasonably determine the damage between order time and the time the order was canceled.
I was thinking the same thing. One could only estimate.
If BFL had delivered 120GH/s to Xian in November 2012 then one could use the earning power of the early Avalons as a comparable case.