Either my post wasn't clear or ppl aren't reading it properly.
The $400k refers to monthly costs of an operation that mines 150 x 25 BTC in that period i.e. ~$1.5m @ $420, or a net profit of >$1m per month.
Re: halving, yes I can divide by two too.
so you really think that someone will sell to you a mining farm for a certain time frame, at a lower cost of what that farm will produce in this time frame? no way this is true
it's like someone do the renting at lower cost than the profit he would have made if mined directly his coins