One items of note. The original post suggested that you are concerned about a timeframe of 1-2 years, I have yet a single example of a miner that has remained profitable to run for one year, much less two. Maybe that will all change in 2015, but I would be reluctant to think about more than 6-9 months for your SP35. This isn't a reflection on the specific hardware choice, just the nature of mining in general.
may not be true. taking price out of the picture. and looking at difficulty machines do not improve much anymore.
cpu = ? watts a gh
gpu 600 watts a gh
asic miner blade 11 watts a gh 55x better
s-1 2 watts a gh 5.5x better
s-3 .8 watts a gh 2.5x better
s-5 .52 watts a gh 1.53x better
asic miner .39 a gh 1.33x better this is a maybe?
