The component with the lowest price in the VALVE schematic is the Nut, Tappet.
The sub assemblies and components that make up this Valve include this Arm,upper Rocker, the most expensive part.
A sample from the products for the Valve include: Seal,valve Stem, Washer,wave 1.5mm, Screw,tappet Adj, Retainer, Vlv Spr.