There is no time is right to buy Bitcoin you can buy when you have the amount of dollar you want to buy with, there are people who haven't heard about Bitcoin yet but if in future they hear about it they will be interested to be an investor….will you say is the right time for them to buy or not the right time due to the rapid increase in Bitcoin one can choose to buy now that is right time for him others can choose to buy tomorrow that is right time for them.
what makes the difference in bitcoin investment is the available cash flow to buy as much as you possibly can, because even if you bought Bitcoin at the current price, you will still be in profits by the time the bull market comes so for me there is no time such as right time to buy Bitcoin regardless of how much you bought it.
It can only mean something she you want to buy a small portion and holding for just short term, but as long as long as it is for the long term then pricing bean all all-time high is still a good buy price for Bitcoin.