It's always a good idea to come up with a strategy for when you're going to buy (and potentially sell) coins rather than just continously aiming to buy a lower price (you're more likely to sell at a loss then too imo).
People would always go for the cheapest price because that means the best moment to buy, but since there is no easy way to make us know that bitcoin price will still drop or not, then waiting for the cheapest price before buying would only mean regretting in the end. It’s better to do DCA than just keep on purely waiting, as you might not want to regret in the end because you miss another golden opportunity again.