The O-ring(36y) is the cheapest item from this partsfiche.
The Xg250 2005 4d61 Norway 1d4d6-352s1 Cilindro consists of four pieces with the Cylinder 1 being the most expensive.
Some items from this specific schematic: Bolt, Socket, Gasket, Cylinder (nas), Cylinder 1, O-ring(36y).