Of all the components that make up this Seat ('83 Kx250-c1) the Bolt,flange,6x12 has the lowest price.
Some items from this specific schematic: Bolt,flange,6x12, Washer,6.5x20x1.6, Seat-assy.
In this schematic the "Washer,6.5x20x1.6" is used most often.