You have got to be kidding me.  You think there's no difference between making $4 per month vs $14 per month?  Really?

Power usage is *everything* when it comes to ASIC.  If you think it's not, you have no grasp on the economics of mining.  ASIC is not CPUs, it's not GPUs and it's not FPGAs.  It's the end of the line for mining technology for the foreseeable future.  What you buy today is what you'll be using in 3 years so long as it's still profitable.  That profitability is determined solely on how power efficient it is. 

If you buy an ASIC device that uses 2x the power as another device for roughly the same price, you might as well throw most of you money into a hole and burn it.