Best Practice users moving their inactive classified ads

[MeMaBlue]

Hello! 

I would like to ask you if anyone has classifieds

and has the users (members)   move their own  finished  classifieds  (topics)  into a  "trashbin"  forum section. 

previously we have had it like this 

members had  specific extra privileges  in the  only certain section that includes all classified ads. 

we have a rule that everyone has to clean up after his classifieds and is allowed only one topic with all his for sale items

because otherwise they are too many. 

to save space the members have to send their own sold /inactive classified (topics)  back to the trashbin forum section

(the trashbin section gets deleted every couple of months )

I need to give them permission to move their own topics,   in specific only (not everywhere)  forums, and be able to move them into the trashbin specifically& only.  (so as to not move somewhere else by mistake). 

I am guessing that those permissions are moderator permissions  

so which is best practice for that,   but i also want to ask  if there is a different way  you would propose or already using that is more functional, with the goal to    save space and remove content that is invalid

(i.e. not available items).

 It has to be member regulated, because there are so many classified ads .