Not really sure.
There’s been a few instances where people linked to something they were selling on gunbroker. Also a few where someone mentioned they were going to be selling something if someone was interested.
In the initial post by TigerLaw he lays down the basic ground rules for this thread.
It’s basically a discussion thread and the main things not allowed are political talk etc.
he didn’t really discuss buying and selling, so I’m not really sure.
I don’t really have an issue with it as long as it’s not someone spamming the thread with crap and is legitimately someone offering to sell something.
As others have mentioned, out of state sales is a little more complicated because there are federal regulations and a firearm would have to be shipped to an FFL holder.