We could even expand this system and start a new round of bets every week.
If a user thinks the post is worth more than it played out within a week he can bet higher and can get curation within a week again.
If a user thinks lower, then it only reduces the value it has to cross to get future payouts.
This would be useful for those posts that continue to provide value long after their initial rewards have been paid. Certain posts explaining features,or linking to resources noobs need to find when they get here, do continue to provide value, and should continue to provide rewards.
Such posts are presently lacking incentive in favor of posts that merely have more impact in the short term, IMHO.