That may or may not end up happening.. then you end up FOMOing in at $50k because you really wanted to buy, but you were too greedy to do it right away.. and you don't even have to buy all of it right away.. but hey people have to make their own decisions, and we have seen a lot of examples historically of guys who were waiting for a lower price an then they become bitter because they failed to buy and they thought for sure that they were right about a lower price was going to happen, and such lower price did not end up happening.
This is the problem.
I think it's better for your regret to be "I should have waited" than "I should have just bought it at $31k"
If he buys now and the price drops, he just needs patience for it to go back up. But if he doesn't buy and the price doesn't go down, he'll end up buying at a higher price.
There is no wrong time to buy Bitcoin. We know that the dip is the best time to buy, but that doesn't mean it's the only time to buy or that buying when the price is up is wrong.