Well we never can tell what will happen with bitcoin by then. 2000 -3000 dollars is also a good amount of money.
I am just hoping as a minimum 5000 dollars or more.
I'm completely different from you. By 2020 only one bitcoin is more than enough to become millionaire. I believe in bitcoin's growth in exponential manner. So, bitcoin will be hitting $10k mark by end of 2016, then 2020 would be year we can see bitcoin will be hitting one millions mark.
It's a bit too optimistic. A realistic optimistic price speculation is 10k$ by 2020 IMHO and that would make a lot of people happy (including me).
100 BTC is definitely a good position (a good bet ?) for the future.
If the price reaches $10k by 2020, 100 bitcoin is worth $1 million. I suggest anybody with the ability to buy 100 bitcoin do that.