Fines seem to me to be a good idea, although I think the example is a bit severe. Looking at current punishments in schools I've seen, high schools in particular, they don't do what they're meant to. Suspension rarely caused the kids much harm, in fact they seem to love it more than they hate it. Detention isn't much better, just a place to put the kids where they do mostly whatever they want, and wastes the teacher's time. In some schools, kids find detention preferable to going home - depending on the state of their home life. Besides, it would prepare them more for the real world, where fining is the most common punishment for breaking even minor laws.
I am a proud member of the Church of Jesus Christ of Latter Day Saints. If you have a question about my religion, please ask me, and I'll see what I can do for you.