Well, I think if someone would try to sell a bunch of stuff ebay-style we would notice that, no? I guess that would be dealt with along the lines of flooding or trolling...That can all be outlined in the rules of the forum.
What I was suggesting was also along the lines of freecycle (thanks LP! I forgot what that was called! LOL) more than sales, however, if for example I want to give my 30 gal aquarium, fully loaded etc - thats quite an expensive item, and I thought it would be nice to be able to sell it for nomnal amount, so someone who is interested, would get it...say for $50, rather than $300? That sort of selling.
I don't know how we would limit the access for people, but I think it should definitely be an active member with no less than 80-100 posts. Or someone who has been with pets.ca for a very long time and signs in regularly, I dunno, but I think its worth looking into. this way, junior members with like 10 posts won't be able to post, but should be able to pm?
The reason I originally thought of this is because I have a bunch of items that are of not much use to me, but someone could benefit from them greatly, and I thought I would have preferred giving it to someone I "know" from pets.ca, rather than some random dude on kijiji or ebay or whatever.