The most reasonably priced component used on the Gs500e 1998 (w) (e02 E04 E18 E22 E24 E25 E34 E37) Speedometer - Tachometer is the Bulb(12v3.4w,t10).
The thirty-four Gs500e 1998 (w) (e02 E04 E18 E22 E24 E25 E34 E37) Speedometer - Tachometer component parts are all listed in this schematic.
The Speedometer - Tachometer assembly is constructed from several parts from which the Speedometer(kilo) (e28) is the most expensive.