At 0.9 J/GH, a full miner would come out to 720-765 Watts, correct?
Using 800 GH/s and 720W over at
https://bitcoinwisdom.com/bitcoin/calculator shows me that network growth would have to average only 10% in order to turn a profit. (This is assuming it takes 20 days from today to start hashing).
I'm on the fence.
no depends on the psu you use. say your 800gh pulling 720 watts from the psu. if your psu is 90% it will pull 800 watts from the wall plug. So my guess is an evga 1300 watt psu will read 800 at the kwatt meter.
so some of the cheaper price is lost back on power.
if compared to a s-3 but for much less price say 100 dollar less then 2 s-3's you burn back 50 cents a day in power or 15 usd a month extra for power. so after 6 months the s-3 is better.
bottom line is btc needs to go up in price after you take delivery on this gear.
I do my roi in usd not btc since I pay tax and do not want to face IRS issues.