The sub assemblies and components that make up this Seat include this Double Seat Assy, the most expensive part.
The component with the lowest price in the SEAT schematic is the Cap, Bolt.
Parts such as the Seat: Om Yn50 '04, Bolt(2yg), Handle, Standing, Holder, Tool are included in the Yn50 2006 1p9b France 1e1p9-332g1 Seat parts fiche.