You have to ask the customer to pay the specific amount for the commission that YOU want, not the low-ball amount, but that one amount, that would make you feel valued, respected and adequately paid. Why you need to do that? Well, because only then you can create your best work, it does not make you feel resentful towards the client and towards yourself for accepting the work that you don’t want to do anyway. If you charge on the low side and you are not happy with the price, but you still accept to work, over time, you become resentful with yourself and the customer, you feel used, you start to rush, to do mediocre work and you don’t even enjoy the process anymore and enjoying the process is VERY important if you are planning on playing the long game. Finally, if something goes wrong during your commission process, you are the only one to blame, because you accepted the customer who can’t or don’t want to pay you adequately and don’t respect you. So say NO way more often, pick the clients very carefully, charge the right amount for your work and remember it’s quality over quantity and it’s a long game!
P.S. Good customers actually understand that they are getting the best work ONLY if they make you feel valued, respected and pay you adequately. So it’s a win-win situation.