What do you think about being able to trade reputation for a decrease in account suspension time? It would still be a punishment, and the amount of reputation lost should be calculated according to the severity of the suspension's reason, and the amount of suspension time decrease a user would like to 'buy'. It would be like paying bail, probably available only in certain moderator-selected cases.
I think this is a very bad idea. Reputation represents your participation in the site. A suspension indicates something you've done is "bad" and outside the normal functioning of the site (where downvotes etc would be the punishment). You shouldn't be able to buy your way out of being a jerk.