It depends on your moral stance about working with the cops in this fashion. In many circles, becoming a CI will get you immediately ostracized and could lead to being physically assaulted. Alternatively you could tell the judge about your financial situation and hopefully work it off via community service. Also, fines can often be reduced by providing documentation demonstrating your income meets specific conditions. But to each their own, I mean based on your citation, what CI work would they have you do? I’ve only ever heard about CI’s in the drug world.