You have to decide NOW how many bitcoins will make you rich in the future because it's getting to the point where an upper middle class American or European can no longer buy a full bitcoin.
Anyone have any ideas how many you'll need to be rich in 2020 and 2025?
If the rising trend of bitcoin continues till 2020-2025,BTC price would be $10k per bitcoin.Also if $ keep its strong position in international market,I think even 5 btc would be enough for one to be rich.
It also depends on which country you live in.