The Rear Brake Mastercylinder (cb600fa/fa3) is made up of components including this M/c Sub Assy,rr which is the most expensive.
The Screw-washer,4x12 is the cheapest item from this partsfiche.
Some items from this specific schematic: Hose Comp A,rr Br, Guide,brk Hose, M/c Sub Assy,rr, O-ring,14.8x2.4.