The component with the lowest price in the CYLINDER HEAD COVER 81-82 schematic is the Washer Seal, 6mm.
Some items from this specific schematic: Bolt,flange,6x50, Bolt,flange,6x25, Oil,seal 17x27x5, Bolt,flange,6x45.
Of all the components used in this assembly the Cover,cylin Head is the most expensive.