Some items from this specific schematic: Clip, Cover, Bolt, Seal Set Pist..
The most reasonably priced component used on the Gs500f 2005 (k5) Usa (e03) Rear Caliper (model K4/k5/k6) is the Bolt.
The sub assemblies and components that make up this Rear Caliper (model K4/k5/k6) include this Caliper Assy, the most expensive part.