Some items from this specific schematic: Bolt,flange 6x20, Duct,air Cleaner, Screw-washer,5x25, Filter,dlain Tube.
The Air Cleaner is made up of components including this Case Comp,air/c which is the most expensive.
The most reasonably priced component used on the Cb250n 1981 (b) England Air Cleaner is the Screw,tapping 3x16.