This needs some explanation because it makes no sense.
Laws are made to set down the minimum standards of behavior. People who exhibit behavior below that standard are punished to deter future behavior that is below that standard. Sometimes we attempt to rehabilitate them too.
A fine is a deterrent. If you were fined two cents, you would not be deterred. If you were fined a few thousand dollars, you would be deterred. If a wealthy man was fined a few thousand dollars, he would not be deterred. We can conclude then that deterrence is relative to the person, not the crime.
What I mean by that is that I do not believe that fines are used as a deterrent, but as a punishment.
A speeding ticket (at least the ones I've gotten), is not a deterrent against future speeding, but a punishment in place of a court hearing for a crime already committed.
While they appear quite similar, you can regulate a punishment but you cannot regulate a deterrent, for one simple reason: you cannot regulate how much someone values something. To deter someone you have to know what's valuable to that person and how can you assess that? You say that a rich person should be fined a greater amount because of the decreased value that he places on an arbitrary amount of money. This is true, for some rich people, but not for all. Most wealthy people that I know love their money and place a higher value on it than I do. Should I be fined more? I love my schooling and knowledge. If I speed, will I be forced to drop a class? As a deterrent, a sliding fine scale doesn't work.
Anyways, that was a round about way of explaining this: justice must be blind. It must assess what has been done and punish what has been done, regardless of who did it. Despite being poor, I am against rich people getting fined more for committing the same crimes, much as I'm against people of other ethnicities getting harsher jail sentences or famous people getting easier sentences for like crimes. Any sentencing that takes into account the individual is no longer just.
