I think the value of bitcoin in the years to come will be hard to forecast. This is simply because of the birth of new cryptos which are now used as an alternative to bitcoin.
Even with altcoins coming out, its not going to affect the price of bitcoin that much. It may work for vice versa. Bitcoin is way far put as compared to the alternatives that are just starting. They may be competitors of bitcoin but none has come close to the support of bitcoin as of present. Bottomline, its hard to forecast the price of bitcoin at all. There are many factors that will play other than competing coins and we never know when a financial crash may occur.