People who say anything about not meeting ROI are ignorant. How can you comment on ROI when you have no idea what the cost of bitcoin will be next week, next month, etc.
Terrible way to look at anything. Just because you don't know things to certain doesn't mean you should be analytical and use the best data available to make a thoughtful decision.
Dont mistake not knowing everything with not knowing anything.
The cost of bitcoin has nothing to do with ROI, unless you pay in dollars.
It is relatively simple. over a period of time t, you spend x bitcoins on electricity, you make y bitcoins, and you spend z bitcoins on the purchase.
Then if y - x > z you have ROI, if y -x = z break even, and if z > y -x over a period t you have a loss.
t is usually 6 weeks.
if you take electricity out of the equation it is even simpler, for roi to occur in a given period of time y > z it is that simple.
to calculate y you can use any calculator that takes into consideration the difficulty increases.
so if bitcoin goes to a 10000, it has nothing to do with roi, since the miner is being being purchased in bitcoins.
the S3 is borderline, it may not roi if difficulty increases at current rate, and since we do not yet know the price of next batch of S3 it will all depend on the price given for the S3, most other miners do not ROI. pre orders do not ROI since it is very difficult tu calculate the difficulty 6 month in advance, or a year in advance. BFL takes over a year to deliver, KNC over half a year from time of order, most take several months situation which is not acceptable.
Since the S3 is selling out at current price, my prediction is that it will not roi by a small margin, until sales slow down then it may be priced at a price in which it may ROI or maybe not since bitmain could start mining themselves. that is why it is very important to support vendors that do not mine themselves and do not have pre orders, currently that does not exist, but in near future it could be a reality.