The component with the lowest price in the SEAT schematic is the Washer, Spring.
The Seat is made up of components including this Double Seat Assy which is the most expensive.
Parts such as the Seat: Double Seat Assy, Bolt, Flange, Washer, Spring, Washer, Plate(j17) are included in the Dt125re 2005 1d03 Turkey 1d1d0-300ea Seat parts fiche.