Some items from this specific schematic: Collar,tensioner, Bolt,flanged,6x20, Washer,10.2x14.5x1.0, Shaft,idler,9x55.
The lowest price component in this Camshaft/chain/tensioner ('81-'8 parts-list fiche is the Washer-plain,6mm.
The most expensive part in this assembly is the Camshaft,valve.