I wondered the same. The bike in my avatar is for sale. I didnt know if we could do that here. I figured people sell their tickets here so I dont know.
Believe this has been asked several times before including by myself and the answer was always unless it's UT tickets the answer was no....I see alot of forums now offering a classifieds section and as long as they (Freak & VN) post clearly that VN is NOT responsible for any transactions between members there shouldn't be any issues. Would be cool to give it a shot for a month or so but don't hold your breath on it.
I see people selling the "I will give my all" signs, artwork, corn hole boards, etc. Just curious as how a car, bike or boat would be any different. And what the appropriate forum would be.