Before you start mining,

The price you pay for power under 10 cents is decent. 20 cents a kwatt is very hard.

5 cents is really good.

So if you have cheap power. How much do you have?

And how tolerant of noise are you?

I could sell you a used 1080ti waterblock rig for about  3500 usd with  

Six 1080tis. It would earn 9 bucks a day. ..

It would be quiet and use about 1200 watts.   That is about three a day in power cost.

So six profit x 600 = 3600

It is paid off In 20 months and the cards have 27 months on warranty.