In as much as Bitcoin is concerned no matter any amount it is anytime, it is better to buy because you don't know what will happen in the next minute in terms of the price increase. Those waiting for the price to go down before buying will be making a very big mistake,these set of investors are not really prepared for Bitcoin accumulation and holding for a Long-term investment, we can say ,they are passer-by .
I agree with that waiting shouldn't be part of anyone who's interested investing in bitcoin as the price volatility doesn't guarantee anything to any one as per it might be on an upward trend but turn out to dip while one might be waiting for a dip it could become so bullish. I always encourage buying regularly (daily weekly and/or monthly) as much as you can within your disposal. Constant buying has proved to be the most appropriate thing one can do in his or her journey in bitcoin investment for instance MSTR ha been buying regardless of the price of bitcoin and it's evidence that bitcoin investment is mostly successful when one buys are all potential including the bullish period.
However buying the dips is not also a bad method of accumulation as long as you're doing it but regular buying (DCA) can be more productive as waiting for the dip might not occur in ones expected times so it's best to make every entry count.