The component with the lowest price in the REAR HUB/BRAKE/CHAIN schematic is the Nut,8mm.
This part-list fiche shows all the components that make up the Km100-a2 1977 Usa Canada / Mph Kph Rear Hub/brake/chain .
The sub assemblies and components that make up this Rear Hub/brake/chain include this Drum Assy,rr Brk,buff, the most expensive part.