Source is doing it before, and being friends with people who have done it at scale. Just go ahead and try to do it. You will find that it's not possible to act

Source is doing it before, and being friends with people who have done it at scale. Just go ahead and try to do it. You will find that it's not possible to actually order stuff from bitmain when mining is profitable at their list prices. It's almost as if they just run the machines themselves when it's profitable, and deliver orders when that is more profitable than using them. So there is effectively a "spot" price for the machines where sellers who have inventory try to extract as much value as they can. Thus, the capital cost is more significant than electrical. (Obviously within reason, but paying 5 cents or 10 cents per kw/h is less relevant than capital cost) I should say though, after the 2018 crash S9s could be had in bulk for $100 each, where they were selling for over $3000 only months earlier. So maybe the flood of these out there makes my experience outdated.