The Rear Brake Mastercylinder (cb600f/f3) 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: O-ring,14.8x2.4, M/c Sub Assy,rr, Nut,hex.,8mm, Guide,brk Hose.