A couple of years back, we experimented with a for sale forum, but, only a few users listed stuff. The moderators did not want the extra work trying to keep scammers off the forum, there was no way for buyers to five feedback on the items they bought, so it went away.
Even though virtually all of our members are honest, they cannout know about buyers who would cheat them, or sellers who signup just to scam someone.
I can recommend the Fred Miranda site to sell your photo items. Fred has customized his forum software to handle it better. He has a nominal fee, its well worth it. Even so, you see a lot of over priced junk being hawked. Trying to sell used for more than the CRW street price for a new item is not that smart.