I do believe in Bitcoin as most of us here, but it has shown its exponential growth only once (!) in its lifetime and it has been out there for quite a short period of time for us to be able to make a long-term projections of its movement and tell whether it will grow that much ever again. We simply don't know as there is no reliable historical data. That is why I'd say if you're willing to take a very high risk then go ahead, invest in bitcoin and God bless you. If you'd like to sleep well without permanent checking the market figures, you should invest into good old property, but be ready to invest some portion of the money you have into Bitcoin... IMHO.
Maybe I'm wrong.