Just a quick suggestion to make life a little easier. Some people don't always put FS/For sale, or WTD/Wanted at the start of their thread. So sometimes it makes it a little confusing if their description wasn't so clear, for example. Furthermore there is no coherence with what people use, sometimes FS, F/S, fs, For sale etc. There are so many different phrases used.
What I suggest is a drop down list, when submitting your thread, between: 'For Sale', 'For Trade', For Sale/Trade' or 'Wanted' to give some coherence. Not only would that eliminate the derivates of the phrases, but if someone has chosen 'For Sale' as opposed to 'For Sale/Trade' then the buyer will know that they don't want to trade, and this will therefore eliminate any unnecessary bumps.
Hope thats clear :)