IN CONCLUSION, 1 unit of Rig Box will earn you $117,502.21 per year. 100 units = $11,750,221 (PER YEAR)
I see no mention of the increased difficulty in your 100 unit example here, you would be adding ~50% extra capacity to the network raising the diff by that much. So once it raised in about a week you would be roughly 1/3 of the network for 2400*$5*365=$4,380,000 returned for the year at a stable price of $5 a coin with free electricity as you don't include that either. And the electricity used would be substantial even for them boxes the ~800mh/s singles get that with ~80 watts from all reports I have seen so 1 watt per 10 mh/s or 500,000 watts for the farm of 100 rig boxes, you would need your own sub-station for that hell maybe even your own power plant. For that kind of energy use I would suggest building in northern Quebec close to James Bay to get some cheap rates directly from a spur line from their hydro plants with the added bonus of it being nice and cool year round saving on the massive AC bill that would be coming your way...
I wasn't aware of the increase in difficulty, can't say I've read that in the official web archives. In terms of electricity, even if I did have to pay, it's just 7 cents per kWh in Ontario(that's per 1000 kWh). The rig box consumes 2,500 w x 24 hours = 60,000 w = 6 kWh x .07 cents = $0.42 per day x 365 days = $153.3 per year per unit x 100 units = $15,330. Taking the above quote into context $15.3k out of 4-11 million is really negligible and even more so of $153.3 out of 117k.
If I wanted to cut my electrical costs, I would get commercial space thus lowering my kWh to 3 cents, cutting elec costs by half.
SORRY HAD TO EDIT MY POST.
