bitcoin price will be around 4000-5000 USD per coin one day and that is already a couple of 100% rises and it will only happen slowly. i think something around 100% rise each year (give or take) is a good estimate of the future rises.
Really this should not happen because many people start afraid to buy bitcoin, already now people are afraid to buy bitcoin even it is at 800$. Bitcoin should change lives of the people not to destroy the bitcoin because only people who have bitcoin will become rich. Once it rises to 4000$ really people will start thinking that it is also one of the hype, so many people stay away from it.