And when its price hit US$300 people will sell some of their bitcoin, then the price will be decreased again. There is just a little chance for its price will reach atleast US$500 for next 2 years imo.
All it needs is fresh demand from new buyers. There's no sign of that on the horizon but future developments might bring that. Right now it's just the same old characters batting coins back and forwards. Unless it manages to break out of its current niche it's not going anywhere.
That also explain why the price goes down all the time. The market cant absorb the new coins that are mined because it is just the same people trading and no newcomers join in.