The component with the lowest price in the THERMOSTAT schematic is the Bolt,flange,6x22.
A sample from the products for the Thermostat include: Thermo Unit Assy, Thermostat Assy., Bolt,flange,6x22, O-ring,47.5x2.
The Thermostat assembly is constructed from several parts from which the Thermo Unit Assy is the most expensive.