I pay US$0.06/Kwh "off peak" and all it does is move the "drop dead" date about two weeks.
This all depends on the Difficulty Factor and value of each BTC - BOTH of these numbers are very "volatile" just now and I don't see that changing for several months.
Once the crooks latch on to a way to make money it is VERY hard to kill them off - just like the small rodent type of rat.
Price per BTC doesn't matter, because if it goes up, you would be better off buying bitcoins directly. If it goes down, you would be better of not doing anything
I would have made more trading so far for sure...but I like the idea of mining better. I pay $.05/kwh all day...it actually might be less since the average for my state (not my area) is .046/kwh (pacific northwest, industrial grade power)...I may end up being one of the last miners...you never know.