The most expensive part in this assembly is the Unit,turn Signal Control.
The most reasonably priced component used on the Gs850g 1981 (x) (e01 E02 E04 E17 E18 E21 E22 E24 E25 E26 E34 E39 Turn Signal Lamp (model X : E2) is the Screw.
With four applications this Screw is the most specified part.