First of all, I would point to how, as I mentioned, the lowest-level government employee can be fired from their job if they're involved in a decision where they have even the appearance of a conflict of interest, even if the decision applies generally. Again, 99% of cabinet ministers' decisions apply generally because they're usually decisions to change laws. It's really only hiring their staff or contracting out that it's a specific decision where the act even applies.
I think a sliding scale of penalties is something that could and should be considered. If you are paid more, the penalties should be higher.