It is never too late to buy bitcoin!!
What do you mean by asking this question? Do you mean is it too late to buy in at 4.2K USD and sell for 5k USD in the same week? I don't understand what your question is exactly.
In the long run the having a free choice is what matters in using Crypto for what we need to do in our life. The best time to buy is now!
Yes,the OP definitely mean is it too late to buy or invest into bitcoin when the price is at the $4000-4500 range. But one thing I study concern the price movement is that the price per bitcoin usually dump by $200 or more when it weekend and my advice to those who really want to make some $$ through bitcoin is to buy or make some invest when it weekend before the market open for the business day.
Well, it's like they say, you buy the dip.
However, if you have a lot of money to invest, and are willing to wait a few years to see the return on your investment, for me Bitcoin is still a great investment, even being a little over $ 4000.