The most reasonably priced component used on the Gn250 1982 (z) Usa (e03) Magneto is the Key.
Parts such as the Magneto: Clamp,generator Lead Wire, Screw 6x30, Screw, Key are included in the Gn250 1982 (z) Usa (e03) Magneto parts fiche.
The most expensive part in this assembly is the Stator Assembly.