Seems to me that what generally seems to happen is that if it's an item that the sellers are happy to see again in a boat being used by someone else then people advertise on YD first, if there are any questions about it's quality/reliability it goes on ebay too. That's my rule of thumb,
I'd add that if it's unsafe IMO ten I don't sell it.
__________________
Give a hungry man a fish and he will eat for a day
Teach a hungry man to fish and he will buy a bad hat
Talk to a hungry man about fishing and you are a consultant.
Safe diving
Pete