This isn't likely something MCG would ever implement, because it essentially allows rule breakers to re-join our servers for a lower price than most donor ranks.
The price really wouldn't neccessarily impact anything either, I think it's just the general idea of allowing people who have broken a rule to just be able to come back with no real punishment.
People are banned for a reason, and being able to pay their way back seems a bit silly, though I can totally see where you're coming from with this idea