I think that you get dealers of some sort doing this a lot. They buy too many units and need to reduce inventory but they can't sell below certain prices per agreements with the manufacterers thus they buy them themselves using their employee discounts and sell them on places like this. Also I know of a couple of home installers who are dealers themselves and sell new gear below retail. NHT is having a big problem with that one right now, it is easy to find their gear at 33% off on the net.
Never Used -- in Sealed Box
Who are the people who keep buying audio equipment, then offering it for sale without even opening the box? There seem to be regular listings for all levels of equipment which have never even been auditioned by their owners. Do these same people ever buy, say, bridges, or Florida beach property? Or do they believe that perhaps we are interested in buying some?