I like to thank all the comments in this thread as it influenced me to buy Bitcoin at $40k in January.

Anytime is the best time to invest in Bitcoin. When governments keep printing paper money causing inflation this increases the value of the finite supply of Bitcoin.
Now is the time to invest according to Bitcoin price, if one wants to invest in Bitcoin with accumulated money then he can do it because the bull market is going to happen next. The bull market is very likely to start in the next few months after the halving, 2025. The highest Bitcoin price increase in 2018 is likely. That is why it would be best to hold Bitcoins now following the DCA method.