The Nut 6mm is the cheapest item from this partsfiche.
Parts such as the 021 - Semimanubri - Ammortizzatore Di Sterzo: Plug, Spring Ring, Clamp Rear, Ring Nut are included in the Superbike 2016 My16 (superbike 1299 Abs) D220-00016 021 - Semimanubri - Ammortizzatore Di Sterzo parts fiche.
Of all the components used in this assembly the Steering Head Base is the most expensive.