Well, mining is self-regulating. The halving is going to hurt a lot, but it's not like bitcoin's going to disappear. What becomes unprofitable to run will no longer be run, coin prices will go up, fees will go up, and the system will keep on running. If anything has a chance to be profitable, it'll be the most efficient chip available at the time. That's dependent a lot on initial cost, but the market is adjustable as well - if BitFury can't sell enough of them at whatever price, they'll either use 'em themselves or lower the price. There are way too many variables to make any sort of accurate prediction, but the fact that pretty soon 99% of the world won't be able to turn a buck with 0.3J/GH gear helps the assumed viability of 0.1J/GH gear.