For Sale Ads now Close 30 days after last posting.

Nothing - but then the item must still be available or they wouldn't be bumping. The whole point here is to keep ads from being posted in when the owner isn't here or the owner forgot to mark the ad as sold. When someone posts in a thread, then its brought to the top of the list. So an ad from 2013 for example, could be top on the list again.
I like the idea of closing after 30 days inactive. But, could they still be marked 'sold' later? I think a lot of guys have gotten better at marking them, so if they can't go back the thread will always look like the item is still available. Effectively making more 'open' threads, just not on the front page. Same with people opening a new thread instead of bumping it. The original thread is still there and looks like it never sold.