I use DCA if indeed my salary results have shown normal conditions and the most I prioritize Buy BTC if my performance benefits are paid so that I also consider it as fresh funds that I can use up to 20% of the total. The important thing is that I have started with real calculations.
I don't quit understand the point you are trying to make because it seems you don't understand much about the use of DCA because from your Statment you seem to presume DCA strategy is only a method that requires huge amount of money before utilizing it because I wonder why you would only use DCA strategy only when your salary is normalized, however I want to inform you that the use of DCA strategy doesn't only involves an investor that has a huge capital but also someone who doesn't have much funds because their is no discrimination in terms of DCA usage.
Perhaps even if you are earning $50 in a monthly basis you can still be consistent on either weekly or monthly accumulation of Bitcoin, for instance since your total monthly funds is $50 you can strategize your accumulation plans to monthly basis using $10 because going above that can easily affect your investment but however if on the process your salary increases or having more other source of income you can then bring it down to a weekly accumulation.
But maybe what he means is that his current monthly salary is not enough to do the DCA method so he says wait for the normal time for his payday, usually so the basic salary is just right for his needs so we assume this is normal because we never know other people's income.
If what he says is more of a lumpsum purchase let alone going to buy bitcoin using 20% lump sum money whatever the method is go ahead if you believe in bitcoin investment do what you can to buy bitcoin as a future asset.
$50 monthly salary will not be enough to make ends meet especially when they already have a family and children then it will not be enough to do DCA but I don't know if in other countries $50 is enough for one month, for me it's better to find other sources of income then these funds can be accumulated for DCA every time you get for example once a month.