I hypothesize that difficulty increase will DOUBLE every 40 days from now until the market is flooded with ASICs

If we use this as a calculation for the difficulty rate in September we get:


15,000,000 x 1.20 ^ 4 =  31,104,000 (difficulty on 16/07/2013)

31,104,000 x 1.40 ^ 4 = 119,489,126 (difficulty on 26/08/2013)

119,489,126 x 1.80 ^ 4 = 1,254, 349,053 (difficulty on 1/09/2013)

These calculations presume that:
120 days till September
12 lots of 10
every 10 days difficulty increases
every 40 days that increase doubles

I hope i am wrong but at these levels even a 350Ghz miner in September wont really be a profitable ROI, even if the price of BTC was 350 USD