The frames should really have the seat springs in order to get good money. A middle or rear seat WITH springs should be anywhere from 200 to 600 or so. So that's about 400 as an average. That translates to about 1200 for a set. But if you're missing one seat, then you'll pay the asking price, right?
Seats are probably more plentiful now as projects and pieces are being sold to raise cash for the little things, you know, like food and mortgages? I think GMONIZ is right on target. Supply and Demand, Caveat Emptor, Timing is Everything, Right place-Right Time---all that good stuff. smile