Some items from this specific schematic: Tube,fuel, Tube,primary Air, Tube Air Pri B, Clip B8,tube.
Of all the components used in this assembly the Tube (550mm) is the most expensive.
The most reasonably priced component used on the Gl1500 Goldwing 1988 (j) Belgium / Kph Tubing (1) (gl1500j) is the Clip B8,tube.