If you are aiming for a long-term then you don't have to worry that much with the prices. In my case, I buy BTC when I deemed that it was below what I consider as the "normal" price which is subjective to me of course. You can do your strategy tho buying every month despite the prices but I suggest to analyze through maybe through the news, if you are doing TA (which I don't familiarize myself yet with this) then you might want to use it or just simply the graph itself. You might want to use these to determine on how much would you buy this month and the next months or would you rather not just by at all yet.