From the trend that is currently happening the price can reach easily 800$.
Everything can happen maybe crash again like before but the price is increasing rapidly.
there is no way we can achieve $800 by the end of this year. unless there is by some miracle a great news and as a result a great number of people invest in bitcoin and then price might go up which is not possible.
$800 by the end of the year is quite optimistic. $500-600 is more like it without further catalyst. $600 is already 50% higher than the start of 2016.