I doubt that Bitcoin will stay in the 150-300$ range for 3 years from now on. Also that chart isn't correct even if it's a logarithmic one: currently we are not at the same level like the top of the bubble in mid-2011. Also predictions on logarithmic scale for multiple year timeframes are impossible in my opinion (see https://bitcointalk.org/index.php?topic=686745.0 for example). Even if the reasoning behind them seems OK, there are simply too many unknown factors which can influence the price.