The Screw,cross,5x16 is the cheapest item from this partsfiche.
Some items from this specific schematic: Bolt, Cover,r.hndl.lev., Nut,hex.,6mm, Cable B Throttle.
With all the components that make up the XR250 1980 (A) USA HANDLE SWITCH / LEVER / CABLE assembly. The Screw,cross,5x16 is the most frequently specified with four applications.