The Screw,tapping,4x12 is the lowest priced item on this Heater Control schematic.
A sample from the products for the Heater Control include: Lid A/c Sw, Band, Harn (over 13), Contl Assy,htr, Screw,tapping,4x12.
The Heater Control assembly is constructed from several parts from which the Contl Assy,htr is the most expensive.