I've sold helmets before, but to friends. They know that I treat my stuff like gold, and they ride with me enough to know that the helmets haven't been crashed. Unless you have detailed knowledge like that about a used helmet, you are taking a risk.
As far as the gross aspect of used helmets: all the helmets I've owned have removable padding, so I throw the pads in the wash from time to time, and wash the shell with soap and water and Voila! no smell/hair/sweat/etc. Something we should all do, even if we aren't selling our helmets Haha
hygeine / grossness is not an issue. you can very easily take it to any sporting equipment cleaning shop and they'll steam clean it for cheap.. it'll come out smelling like roses. I did all of my hockey gear - skates to helmet and everythign in between for less than $100... a helmet would probably be $10 or something.
The only issue is the integrity of the helmet.. if you know and/or trust the guy you're buying it from, and it's not been in any major crashes... then I don't see a problem. There's always exceptions.. people win shit, people buy stuff that they find out they don't like, people get gifts... just because it's "used".. doesn't mean it's junk... but you always have to beware.
Unsecure image, only https images allowed: http://i140.photobucket.com/albums/r1/YZ12588/helmet.jpg This helmet is absolutley FINISHED.. It took the impact of a YZ 125 at about 100km/h. I was actually pretty bumbed, because this was my second ride with this helmet, but it did its job. I did get knocked out and I did have concussion.. but Im alright I wanted to make it look good so I could put it on my shelf, so I glued the nose cone back on and put on my spair peak and it looks like a brand new helmet..(with a few scratches)
I would never buy a used helmet, and at this stage Im replacing my helmet about every 8 months( I crash too much), you only have one head..
If you have a cheap head, buy a cheap helmet..
Do you want to end up living like a vegatable the rest of your life because you bought a broken helmet? It can happen.. Im not saying it will, but it can..
i had a feeling that i shuld def go new, but i just wanted to make sure i wasnt passing up an opputrunity to save some money without compromising my safety. but speaking of cleaning gear i have to get my hockey gear cleaned. but what companies would serve a good purpose for a basic fullface? is bell a joke or shuld i save up and go for something like fox
like most people have said so far, it may be a bit risky and you might end up hurting your self because the helmet could be broken, but if your buying from a close friend or relative, then most likely it would probably be safe because your friends and family won't try to scam you (at least mine won't when it comes to safety.)