Fines are to discourage wrong /illegal behavior. If you can't pay the fine, don't do the crime. It's really that simple. In addition to the fine, gear confiscation would be great, as would loss of license privileges.
It really doesn't matter to me what it cost the state to raise a fish, and has nothing to do with selective, C & R or put and take fisheries. It has to do with abidding by the established laws.