The DCA method is very helpful for me to locate bitcoin from last year, and it is very helpful. I agree we don't need to buy 1 BTC, but we buy according to the money we have. For example, if we have $100, we can buy that amount. So even though bitcoin is expensive we can buy it as much as we can afford it
Why do you have difficulty finding the location of Bitcoin prices from last year? you can see it on coinmarketcap, apart from that you also have to record all purchases in notes or excel as an important note for you because so far the exchange has only limited the traces of buying and selling transactions with the capital you use.
What this means is that I have purchased bitcoin using the DCA method from last year, and this method is quite effective. I didn't record my bitcoin purchase price because maybe I just remembered it.
If you remember that you last bought bitcoin last year then you don't have to write it all down, what is clear is that you still remember the last time you bought bitcoin, that way you will know when is the right time to sell bitcoin and withdraw the profit you can get.