The option to invest is for people who can save some part of their income. There is no need to consider saving if all you earn is what you need to survive. However, one can still increase his earnings by acquiring skills that can make him earn higher or seek other means of getting extra income.
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Investment must be with full awareness and control over one's finances. If they still have bills and needs to be met, then they must prioritize them and postpone their investment first. However, if they can allocate some of their money for investment, then they can do DCA to buy Bitcoin slowly in small amounts. Increasing income or reducing the amount of expenses can be an option for them to invest, but it must be done consistently to achieve maximum results.
In as much as taken care of personal expenses can be very important and essential over prioritizing it can also make a lot of people not to become investment oriented such that instead of curtailing or cutting down budgets they will increase to maintain or upgrade lifestyles that might not be optimally necessary, but yeah undoubtedly people can never have the same mentality and that is life generally. However, one could actually cut down budgets in such a way that it will not have negative impact on their living expenses, for example one buy a less expensive car instead of an expensive one, go on a vacation once in a while rather than usual, eat out side once in a while than usual maintain things that can still be maintained instead of going for a new one, just to achieve this future plans(investment).