The price is speculative. Research what Keynes said on speculation. As much of a BTC fan I am myself, the current price level is that of one that has been determined by speculation and enterprise together. Definitely an interesting mix of the two but that's probably why there's been such high growth over such a short amount of time.
How else can price be established? Price discovery, when unregulated, it's going to be erratic. So you either want regulation to have a (fake) stable price, or a real, but volatile price.
The good news is, once BTC has an huge monetary mass worth trillions like gold, it will be more stable, and early investors will reap the benefits, as it should be in any non communist state.