Anyone that knows stocks and how the market works may know the answer to this, I sure would like to know a guesstamate.lol
The standard answer is that the most probable future value is todays value (efficient market hypothesis). However the market for Bitcoins is somewhat illiquid, and the EMH is controversial, anyway.
In Bitcoins case the random variable dominating all others is future adoption.
Current market prices imply lots of future growth, I would say about 100x. If people believe this growth will not be realized, prices will fall and if it looks like this growth will be exceeded, prices will rise.