Goldman Sachs gave up their predictions around the $4000 ish mark. Why should be listen to anyone else? It'll do what it's going to do. That price is possible. It would be a deeper fall than 2013 but not by very much, but it'll take something pretty radical for it to happen.
Though all of this could be argued since all of them are just mere predictions. But from the article in the OP, giving the exact amount would be very intriguing. I am not aware of what really happened about the 2013 crash, I know it involved Mt. Goxx but I have no idea about the details. Supposing that 2018 will be like 2013, wouldn't it much more practical to drop at around 10k - 8k rather than that very low price? I mean, come on. Would whales and strong investors would wait for the price to reach that bottom. Seeing BTC at 10k would be a good entry point for them, right?