I think that in order to properly estimate the expected price after Halving should look at the schedule difficulty and hash rate. If the miners begin to massively roll up, the price will be able to stay at less than double the price in April-May, that is, less than $ 800 dollars. Otherwise, ie if the miners would have enough patience (and stocks) not to sell Bitcoins cheaper and continue to main unabated, a new stable level will be somewhere between $ 800 and $ 1,000
Miners make money by generating more income than they spend on electricity and the associated costs of running a network of machines that are always churning away. Maximizing profit in bitcoin mining is all about how much hardware someone can throw at trying to solve the next block.
The more hashing power, the more likely a miner is going to succeed on a regular basis.