I run into so many customers who already own Bose *uhgh, the vomit wells up when I even type it*, I offer to trade in the Bose stuff (or other decent used gear) in for current ebay value and take care of selling it. I use the money as credit towards a new system.

I just UPSed one off today. It definitely gives people more motovation to upgrade if they set some value for their current stuff.