The component with the lowest price in the E-5 THERMOSTAT schematic is the Bolt,flange,6x40.
Of all the components used in this assembly the Thermo Unit Assy is the most expensive.
The O Ring 21.9x2.5 is the most widely applied product in the GL1200A GOLDWING ASPENCADE 1987 (H) E-5 THERMOSTAT ( four times ).