Seems to me that if you wanted to mine coin, the most cost effective way to do so would be to provide your own electricity. It would cost more up front, but a small grid of solar panels and the required hardware could generate and store the power needed for a system. Once paid off (kinda like the psu that you supplied to turn the unit on) the system would run basically for free. Solar can prolly be amortized, and depreciated as well, if trying to run as a business?

Stay cool out there.

Wub