The Gsxr750 1998 (w) (e02 E04 E18 E22 E24 E25 E34 E39) Muffler consists of seventeen pieces with the Exhaust Comp being the most expensive.
Parts such as the Muffler: Gasket,muffler Joint, Bolt, O Ring(d:1.9,id:7.8), Body,muffler are included in the Gsxr750 1998 (w) (e02 E04 E18 E22 E24 E25 E34 E39) Muffler parts fiche.
The component with the lowest price in the MUFFLER schematic is the Washer (8.2x24x1.6).