cool. so some countries already have % of income based fines.
Over there the judge has some leeway for creative sentencing. I remember this case where one fellow ran the numbers and figured it would be cheaper for him to pay the occasional fine for parking in a no-parking zone than pay the parking meter. This didn't go down well with the judge, he argued that road signs are not made to look pretty, they serve to regulate traffic on the public roadways. That fellow had to hand in his license, he was banned from the road for five years, and a re-application after a ban involves a chat with a traffic psychologist.
I regularly parked in resident parking areas, getting tickets perhaps half the time, rather than the certainty of a higher price in a garage.
As an engineer, that seemed perfectly reasonable to me. (Resident parking violations are now much more expensive, so this loophole is largely fixed.)
But it was a bad thing to do, because you were taking parking spaces from the people they were for. Their fine structure was broken, but your moral calculus was the problem.
If you get a $10 fine from one person and a $1MM fine from another person, you have every incentive to make sure the latter person is the one you catch.