Suggestion:
How about separating the wanted ads onto their own bulletin board, WITHOUT usernames/ID's posted. Then allow responses to wanted ads to be posted on the same bulletin board using the traditional rules, so that buyer responds to seller in the usual format.
How about separating the wanted ads onto their own bulletin board, WITHOUT usernames/ID's posted. Then allow responses to wanted ads to be posted on the same bulletin board using the traditional rules, so that buyer responds to seller in the usual format.