The Sv650 2007 (k7) Usa (e03) Gasket Set consists of eighteen pieces with the Gasket Set (nas) being the most expensive.
On this parts fiche the Washer(10.6x25.5x2.3) is the most specified component.
The component with the lowest price in the GASKET SET schematic is the O Ring(d:3.1,id:22.7).