There is no guarantee that the price of bitcoin will double a few years from now, but according to the price valuation it might rise a lot five years from now,that is just a speculation and an assumption,always have your eye in where ever you invest.
But as we are reaching the total supply limit, demand will increase and few bitcoins will circulate in the market. There's a chance that the price of bitcoin can get up higher than Op's expectation but I don't have timeframe on when it's going to happen. What is the best thing to do is just hold your bitcoin and be patient.