Some items from this specific schematic: Gasket,breather P (nas), Cover Comp,cyln H, Bolt,head Cover, Gasket,head Cover (nas).
The most reasonably priced component used on the Cb600f 1998 (w) Australia Kph Cylinder Head Cover is the Rubber,mount.
The Cylinder Head Cover assembly is constructed from several parts from which the Cover Comp,cyln H is the most expensive.