The problem with some people is that they can't tell the difference between their important need and the unimportant ones(wants). Someone that wants to invest into Bitcoin will always want to settle their needs first but when the salary comes, they realise that they have nothing left as discretionary income after budgeting every bills down. Reason is because they've pured the whole money into things that are necessary and not necessary (planning to buy an expensive designer shoes or clothes, or budgeting for things that are trending or eating out frequently).
There is nothing wrong in enjoying yourself once in a while or buying some nice things for yourself. Investing into bitcoin should not strangle you or make you stop caring for yourself and about your looks. There should be a balance and adequate planning to contain all these life necessities and still priorities investing. I agree that some people can get excessive with their spending which is not entirely good, but total absence of these relaxation or things that makes you look nice makes investment look more like a burden than securing your financial future. You could go ahead and save for them for sometime and get them when you've enough, it shouldn't be a threat to your consistent buys, you can always divide your discretionary income into 3 equal parts(investment fund, savings and discretionary consumption) and keep saving that 33% for discretionary consumption until it is enough to handle such nice treats you want for yourself while you keep investing and building backup funds simultaneously.
The 33%-33%-33% division may not be applicable for everyone. Because not everyone's income, expenses and responsibilities are the same. There are many whose backup fund is already strong, while some have so many responsibilities that if the backup fund is zero, it becomes more important to make it strong as well as dca in bitcoin .
Then the investment in Bitcoin and the backup fund money may have to be divided and allocated as about 50%/50%. When investing in Bitcoin from discretionary income, the fund should be allocated in such a way that sustainability is important. The person who will invest will decide this by calculating his financial status and expenses.
I personally am not in favor of keeping such a fixed ratio. A person will make DCA from discretionary income according to his financial status at that time and put it in the backup fund. And dividing the emergency fund, reserve fund type in the backup fund may seem complicated to a new investor in the beginning. So the simple thing is a person will create a backup fund and invest in Bitcoin according to his convenience.