The most reasonably priced component used on the Wr250f 2001 5ph4 Canada 115ph-100e3 Oil Pump is the Circlip(1wg).
This schematic depicts all components used in the Wr250f 2001 5ph4 Canada 115ph-100e3 Oil Pump partslist.
The Oil Pump is made up of components including this Oil Pump Assy which is the most expensive.