Take Antminer S2 for example, 1000w and 1TH, $3900, at 20% difficulty increase, it can mine maximum 5 coins during its life time, means each coin cost at least $780, electricity cost excluded
Although the current exchange rate is far below it, all those mining rigs were wiped out immediately after announcement
I anticipate that there will be a large scale sell off for 1/2 generation ASICs soon and those who live in north might purchase them to warm their garage. And who sold their rigs will use those money to purchase coins