1. We used to have a plug-in that allowed users to change the thread tag from For Sale to SOLD That plug-in doesn't work with our current version of the forum but we are looking into getting it updated.
2. I get lots of "What's it Worth" threads in the discussion forums. We don't talk sales in discussion forums so they can search old ads to see what things went for previously.
3. There's no reason to Delete old threads as it's counter-productive. The resources consumed by the thread are less expensive than a person to go through and search and delete old ads.
Expired ads expire on their own. They are there t o indicate that the thread has been abandoned by the OP and has not refreshed it.