ps. I don't think cost of mining is important at all! because you may think it is $7000 now and say price won't fall below that but it may fall and then if it falls below $7000 the cost of mining will be reduced to $6000 and so on.
These topics and arguments emerge occasionally now and then where some people claim that the price can't fall below some cost of mining. Obviously, this is nowhere near how things stand in reality. First, there is no certain cost of mining because every miner has different costs even if his fellow miners have the same electricity prices or the same equipment. And then, miners don't dictate prices, prices are determined by the market, while the role and importance of miners has long seized to be a factor there.