That's really hard to tell. But it seems to be not possible to happen within just 3 years of time. Although the rate of increase on its value is already at this moment, the problem is we don't know until when will it maintain a rate as high as this. In my opinom it will achieve a market value of 20000$ 3 years from now and I think, it is mor realistic and quite possible to happen than to reach 500000$ on the given period.