The component with the lowest price in the CAMSHAFT/VALVE schematic is the Cotter,valve.
The Camshaft/valve is made up of components including this Cam Shaft Comp,in which is the most expensive.
Some items from this specific schematic: Lifter,valve, Shim,tappet (1.80, Shim,tappet (1.55, Shim,tappet (2.85.