Except… it is fair? Because it’s proportionate. I don’t get what’s difficult about that. An impoverished person paying $400 dollar fine isn’t the same as a millionaire paying the same amount. For the poor person, $400 dollars could mean starving. Would you really claim it would have the same consequence for a rich man? Would it even be noticeable to him, while the absence of food in their stomach would be glaring to a poorer man? Would it be fair for a man to starve for the same crime as a man that would be having a three course meal?

By taking income into account, it allows the impoverished able to still survive while paying any fines they may incur. And, ultimately, while $100,000 dollars would be noticeable to a millionaire, they would still get by. And, assuming the law is properly implemented, they would be paying the same equivalent of their yearly income that a poorer person would. That’s what makes it fair. They would be impacted the same way - but you are looking at the amount rather than the equation.

Also, it’s important to make sure that even the rich would pause at the cost of a fine. They need to fear the law just as a poor man does.