The component with the lowest price in the F-30 THERMOSTAT schematic is the Bolt,flange,6x20.
Some items from this specific schematic: O-ring,47.5x2, Bolt,flange,6x20, Bolt,special,8mm, Case,thermostat.
The F-30 Thermostat is made up of components including this Thermo Unit Assy which is the most expensive.