I don't know what.... I agree with David that it's serious to be in a conflict of interest, but again, it's not necessarily corruption.
I think the best thing to do in a conflict of interest situation is for the official to have a chance to remedy it and to apologize and acknowledge it. However, in cases where that doesn't happen, yes, I think there should be fines, and they should be significant. As for what the amount should be, I don't know.