With regard to the 20 year rule, of course.
I remember this thread from a little while ago.
http://www.reddit.com/r/AskHistorians/comments/29hmmd/has_a_territory_ever_purchased_their_independence/cil7lx9
It's a pretty good read.
hi.. some info and more links here
How significant was the damage done to Haiti by the damages they were forced to pay for their rebellion?