For sure any of us can make mistakes of attempting to be overly strategic in regards to buying dips, and I am pretty sure i have been arguing these points until I am blue in the face, and sometimes when we are focusing on buying the dip, we may well end up with a lower cost basis (possibly and possibly not like you suggested) but then we also might end up with fewer coins too..   There is a certain amount of value to continuing to accumulate BTC, and yeah sometimes if the price dips then we are kicking ourselves for mostly running out of fiat to buy more, but we cannot really know that we would have been able to buy more BTC merely because we ended up hanging onto a lot of fiat rather than just regularly and ongoingly buying BTC.

And yeah, maybe buying on dip does become more of a luxury (and/or advantage) of the guy who already reached his/her BTC accumulation target or is well on the road to getting there.

Let's say for example, you are aiming to get 1 years salary into bitcoin in 5 years or less, so you already realize that you have to try to invest at least 20% of your salary into bitcoin to just get to that point, and sure maybe you might feel that 20% is pushing it, and maybe you figure that you might be able to get some cheaper bitcoin by waiting for dips, but maybe in the end, it might not really matter, so maybe you should just be using the whole of that 20% to buy BTC every week (or whatever is your purchasing frequency) and if you happen to come across more cash because you got a bonus or because you were able to cut some of your expenses, then maybe you might want to hold that extra cash on the side for buying more on dips..

but then maybe overall you are feeling that you need to get to one year's salary invested into bitcoin before you might be able to relax a bit in your BTC accumulation methods, and sometimes these are kinds of artificial and somewhat arbitrary goals, but they might also be indicators that you might start to feel that you are in a position to be more flexible with your style of investing.   

There can be a bit of anal-retentive behaviors involved in figuring out these kinds of passages of thresholds.  I believe that I got to higher levels of being able to relax about my bitcoin holdings at 3 different stages. The first was getting above 10% of my investment portfolio into it.  The second was when my BTC portfolio was in profits, and the third was when my BTC holdings started to equal the value of all of my other investments (which was when it got to 50% of the value of my total investment portfolio due to the lopsidedness in BTC's price performance in comparison to my other assets).   As I am listing these, they sound so arbitrary, and so it seems to me that individuals are going to cross these kinds of thresholds at differing points, and the crossing of the thresholds might thereafter cause them to go through a review of their whole approach and perhaps make some adjustments to their style based on crossing over these kinds of thresholds.

By the way, getting to fuck you status could be another one, and surely I would expect that most bitcoiners are likely to have other investments, besides bitcoin and cash by the time they get to fuck you status, but there still could be some bitcoiners who do not have a lot of different kinds of assets, and surely there might be challenges to have fewer assets, but there are likely ways to accomplish that.. and at the same time, sometimes the BTC holdings might feel like it is the only thing that a person has when it is outperforming and dwarfing all other assets in your investment portfolio.. .so there could become some questions about selling off some of the BTC, merely to not have so much value in one asset.. and there could be some assurance that might come from just having some stock index funds, some property or maybe some other kinds of investments that hold somewhat steady, even if some of them might have expenses associated with owning them.