The most reasonably priced component used on the Fz750 1991 3kt3 Europe 213ks-300e1 Fuel Tank is the Washer,spring.
Some items from this specific schematic: Clamp, Pipe 2, Damper, Locating 2, Fuel Tank Comp.(gray/blackblue.
This Fuel Tank Comp. (white/gray) is the most expensive of the items that make up this Fuel Tank assembly.