Well, assuming you've got the right model number (Yamaha has had a LOT of gear over the years for both sound and motorcycles that were model "something1000".)
It depends upon the configuration, but I've seen them being offered on the Internet for anywhere from $3200 and up. Heck, do a Teoma or Google search yourself and find the TV broadcast facility selling their used one for 1600 pounds sterling.
That's why I find that $400 price awfully fishy; soundling like either an extremely hot item or an extremely malfunctioning one.
G.