The most reasonably priced component used on the Gs750ec 1978 (c) Usa (e03) Front Wheel (gs750ec is the Cotter Pin.
Some items from this specific schematic: Bearing, Dust Seal,speedometer Gear Box, Balancer,wheel, Nut 12mm.
The Front Wheel (gs750ec assembly is constructed from several parts from which the 54111-47604-12u is the most expensive.