My local salveage company sells beds for $600-$800 depending on their condition. They also sell tailgates for $100-$150, again depending on condition. Here they are usually in good-excellent condition because we do not use salt on the roads, might be different in your area.
Several members of this forum and other forums are doing drw->srw or srw->drw conversions, maybe someone would want your bed/tailgate, try advertising them on the different forums. Nice that we can bolt up a srw wheel to the dually axle w/o having to swap the axle and only have to add a 2" spacer up front to get them in the same tracking.
CD