Of all the components used in this assembly the Lamp-head is the most expensive.
A sample from the products for the Headlight(s) include: Screw,focus Adjust,4x, Bulb,12v-60155w, Screw-pan Head,5mm, Nut,5mm.
The component with the lowest price in the HEADLIGHT(S) schematic is the Screw-pan-cros,5x12.