it's a good thing measuring theoretical max production, but you have to find someone that will buy your product then (at the price you've chose). I think that every ASIC vendor will need to lower their product price inevitably. I just don't know what will be the price equilibrium, my gut tells me something along 0.5 to 1.5 GH/s should be correct, but I'm just guessing.
You mean $0.5 to $1.5 per GH?
yes, but for a full working plug'n'play miner
I think its even lower. The more cost effective asic designs would be below $0.1 per GH for the bare chip:
https://bitcointalk.org/index.php?topic=295270.0PCB, cooling, case etc may double or triple that, but not more than that in large volumes.
Another thing that will determine the price is the power consumption, but I think they'll be able to lower it significantly as well.