Hello,
There're two options for you not to look so pessimistic (ridiculous) here:

1). just use whattomine.com - my working machines (let's assume s9 13.5 TH/s) will payback for 9 months from now on with my NON-cheap electricity (I'm paying 3.6 RUB per KW/h e.q. 5.2 cents). If you have electricity for 3.5-4 cent per KW/h then payback will be in 6-7 months.
If you want your payback for the less time then either you're an optimist or your electricity is freakin' damn COSTLY.

2). not to write such things showing that you have never mined on an industrial scale before