If you make $550 per day, $40 is 7% of your daily income; if you make $82 per day, it's 49%. That's not the same for everyone. Of course, there are people who make well more than $550 per day and people who make significantly less than $82 per day.
By that logic, almost every single rule in this world is 'unfair' towards the poor, because of course things cost disproportionately more for the poor.
($200,000/365=$550; $30,000/365=$82)