The idea of getting started does not necessarily mean that anyone needs to start by investing a lot, and the getting started causes them to have to learn more about how bitcoin works and where to get price exposure.
Most people should have some general idea about how much discretionary income that they have, so even a person who knows that they have $100 per week that they could invest into bitcoin, might decide to start with $20-$30 per week while they are investigating further into bitcoin, and maybe it takes them several weeks or even several months to get more comfortable that they feel more comfortable to increase their DCA amount to perhaps $50 per week, and after some time they might be able to figure out how to increase their income and/or to decrease their expenses, so that they have $150 or $200 per week that they could invest into bitcoin, but they might decide to increase their investment to $80 or $100 per week at some point later down the road.
I think anyone with the idea that investing in Bitcoin requires a lot of money and to learn all about how Bitcoin investment works may be misinformed or has gotten the wrong knowledge because Bitcoin investments is one of the most less stressful form of investment because with the DCA, the ease to invest is already there without feeling pressured of any kind since you are investing with what you can afford at different periods of time and just like your illustrations, anyone can begin at any discretion so far as they are not affected in other areas so when we talk about investing same amount at different intervals of time does not really we can not increase or reduce our DCAing amount in the future when our source of income has appreciated or depreciated.
Maybe they only look at the value and think about its expensive to start investing with this coin. But they failed to realize that they could start at what they can afford to have since any amount will do and for sure that once they start they think about to do more better to and try to earn more so that they can add something to their investment with bitcoin.
What cool about bitcoin is they don't need to pressure their selves to exert a lot of efforts since simple buying and holding for long time could bring something good result in future especially if their belief in bitcoin is so strong. If they are confused on the amount to use then maybe they should calculate all their expenses first and take care those important things then they can use the extra funds left from their earnings. Although figures may come up different then its fine as long as they are consistent and everything should be fine on their investments.