This time, the price of bitcoin is really far from the $ 100 price. if you're really waiting for bitcoin prices dropped to $ 100, I think, you're going to wait for it for life, because I am absolutely convinced, bitcoin prices will not arrive at that price again.
We cannot deny that fact that bitcoins price will no longer go back to 100$ and if you wait for that value to return you will just end up waiting for nothing. The only profit you will earn from waiting is regret and so if you have the chance to invest in bitcoins today then do it now and not wait for tomorrow. The main reason why we must buy bitcoin now is because the price tomorrow may be higher than it is today.