You wish!

You seem to think hardware prices will remain steady, in reality they will drop as fast as difficulty shoots up. Cointerra preorders are already being discounted at a rate of 50% per month now, not surprisingly perfectly in tune with D doubling per month,  and thats not going to stop until marginal production cost approaches mining profitability per TH.

The latter is easy to calculate (I went with cointerra's specs), but the question is, how much does it cost to make more 28nm asics ? I did the math in another thread given a $5000 price tag per 28nm wafer  (generous) and 2-3x cost for stuff like testing, packaging, PCBs and vendor markup, and it  results in a difficulty somewhere between 100 and 200 billion at todays BTC exchange rate and with EU electricity prices. Thats a ballpark figure, it may end up being half that or double that, but not 1/15th of that, no way.

I cant predict how fast we will reach those levels, it could be many years,  but the only thing limiting that is the ability of all asic vendors combined to produce and ship their products. There is no other limit. Considering the amount of vendors and the fact that at least some of them will be able to manage a supply chain better than BFL, I wouldnt be too surprised to see this happen in less than two years.