What about someone that does not have a discretionary income yet the person knows how to manage his or her investment without all of that mentioned yet invest on it very well and become stable in the investment stronger and better than those that are financially stable buoyant . when it comes to source of income been consistent in ur investment can help you reach and figure out ur goal and sustainable desires in life ur important needs and achievement.
I think you're misunderstanding this what discretionary income is all about, first discretionary income is leftover money after you must have settled your basic needs and expenses either for the week or for the month. So in other for you to be able to invest in bitcoin you need to have a discretionary income, discretionary income is the money you will use to invest in bitcoin and not money made for your basic needs and expenses. And also from your discretionary income you set up your emergency fund and backup fund, to enable not to temper with your bitcoin investment when emergencies arises.