as there are options on the market that are much more cost effective at the moment (Terrahash, Bitfury, KnC, etc.)
A bit offtopic:
did you took time variable in your caclulations ?
No, obviously I didn't. ATM it's impossible to know exactly when batch #3 will be delivered, even less when the Bitfury o Terrahash will be able to ship en mass.
What I'm quite sure about is that above 30/35 million difficulty, Avalon batch #3 won't even break-even.