The most reasonably priced component used on the Ds80 1981 (x) Usa (e03) Oil Pump is the Gasket(6.2x11x1).2 (nas).
This Pump Assembly,oil is the most expensive of the items that make up this Oil Pump assembly.
Some items from this specific schematic: Cap,oil Pump Inspection, Clip, Hose,no.2, Hose,oil No.1.