The component with the lowest price in the SOLENOID VALVE schematic is the Bolt,flange,6x12.
Some items from this specific schematic: Valve Comp.,air J, Valve Comp.,air J, Joint,three Way, Tube,5.5x90 (w20).
The Solenoid Valve is made up of components including this Sol.vlv.comp,aicv which is the most expensive.