Tera's bottom call was $3000 and said that was "generous" and wouldn't be surprised if it went to $1000 again.  My call was more generous and was something like $4200-4400 just from looking at how other bubbles besides bitcoin have behaved.  Regardless, there should be a long drawn out bear market after that parabolic blow-off top at $20k and it's going to go sideways at some number you will not like for many months/over a year.  

It's also possible there's a large amount of miners all with the same production costs and mining equipment that will be playing chicken with each other to see who turns off their millions of dollars of equipment first that will further erode the price support, like how KNC went bankrupt during the last bear market.  You will end up with some kind of stupid situation where Bitfury goes bankrupt and only Bitmain is left or something, or vice versa.