The component with the lowest price in the OIL PUMP schematic is the Circlip-type-c,11mm.
The sub assemblies and components that make up this Oil Pump include this Pump-assy-oil, the most expensive part.
Parts such as the Oil Pump: Rotor-pump,inner, Filter-assy-oil, Bolt,6x12, O-ring, 22m/m are included in the Er500b3 Er5 1999 France Nl Fg Oil Pump parts fiche.