You are too optimistic to predict 1 BNB = $ 100. This will never happen. If so I am sure that BNB will become the number one cryptocurrency in the market. You can buy BNB anytime and don't care about its price. Because it is Binance's coin and it is very potential.
If BNB price will be 100$ than it's cross Ethereum and number one coins but i don't think BNB can be overtake this challenge. This is Binance coin so any amount invest is worth and it will be massive profit investment in the future. It's continuously pumping now 16$ reached finally and this month will grow 20$ i hope.