6920 then 5200 then 6500 then capitulation around 3K in january 2019
With this difficulty there's close to 0% chance for ever getting back to $3000. Yes, electricity prices * difficulty are not directly correlated to BTC price, obviously, but no miner can afford to subsidize electricity costs to BTC network. You can not operate with a long terms loss, they will simply:
a) turn off the machines, or
b) stop dumping immediately what has being mined, making permanent bottom on break-even price level.
Guess which one is more likely to happen.
Bitmain just announced that it has finally developed a better ASIC chip. It will be 42J/TH. Bitfury also announce that they have a new ASIC chip which gets 55mW/GH.
https://www.coindesk.com/bitmain-ceo-announces-new-7nm-bitcoin-mining-chip. I put in some figures, and it appears at the current difficulty and 5 cents/kwH price in China, that brings the electricity cost down to less than $1,500 USD to produce 1 BTC. If the difficulty doubles, it will still be less then $3000 USD to produce a BTC. And I suspect some of the larger mining farms in China are getting a better deal than 5 cents/kwH. Therefore, the break-even floor is going to be lowered.
However, I really don't think BTC is going to go much below 5000 USD. After all,
Bitcoin core just patched up a major bug that was present for almost 2 years, and the market responded like it was just noise. 
Kinda concerning really. Is that last bug and we're all fixed now? Whew!
Inflationary bug? First I've heard inflation was actually possible for btc.
What is the likelihood it was planted there intentionally? Maybe someone just discovered a hidden pot of bear juice. Sorry, gotta ask cause that's a pretty big banana.