I think anyone who is accumulating bitcoin for the long term should not concentrate more on the pumping of bitcoin, because you will be holding your bitcoin for at least 4–5 years. Your main focus should be on how you will consistently accumulate the quantity of bitcoin you want to hold within the time you set aside and also hold it until the year you want to sell it.
This is just the summary of the whole thing. Instead of the back and forth argument of which buying method is best and which is not, just accumulate Bitcoin, save it properly and give it time to grow. No one will care if you bought all your Bitcoin once or if you bought it in several stages, as long as you have a good stash of Bitcoin which you collected and preserved for the long run.
What I have come to understand is that when the investor have a target in terms of quantity of Bitcoin he is working towards having, it will better influence his buying pattern and how aggressive he will become. For instance, an investor who set target of 2BTC in five years mostly be more aggressive than another investor who have no target. I think setting targets in terms of the quantity of Bitcoin to achieve, should be highly encouraged.
Setting a target of how many BTC you have is good because you will have confidence that it can reach the goal by any means, including DCA and DIP all means are done to accumulate bitcoin until they are satisfied with the results they have.
Actually this will not be easy considering the expensive price and then with your financial stability for the next few years because it must also be considered, don't let you focus too aggressively on buying bitcoin at the beginning but after running half of it you have problems and don't have an emergency fund then it will cut the btc you have, so the initial concept will break because there is no emergency fund.
It always depends on your plans since you are the one who can set your goals towards your accumulation and what you want to achieve also it depends on you the timeline of your accumulation then the methods you want to use.
I don't think it will matter on the price since people can decide to accumulate depends on how many satoshi they can afford and everything is fine on any amount as long as they accumulate then have something to stake for future. But investor should make sure that everything on their side has settle and they will not encounter any problems while accumulating since if they don't have back up funds or separated emergency funds then chances for their plans to fail is high. That's why its better if they are fully prepared on each decision they want to do so they can assure success on their holding plans and can get a good profit in future.