Nobody will know what the value will be in 2020 and that is because Bitcoin is a currency and you can never predict a currency and that is the problem, it is just wait and see.
But I think that Bitcoin is getting be more used and that would be nice for the currency itself.
Nobody can predict the future that's true, but my opinion is that in 2020 bitcoin will be spread in more countries than now and we can expect a great change in the price values too.