Volvo does not supply replacement headlight lenses in the U.S. market. I guess they figure we're not smart enough to replace them without hurting ourselves. The 850 lenses you talk about are aftermarket or available overseas. The Volvo parts catalogue lists a replacement lens and gasket for 850 models, but not available in U.S. Plus, to replace the S-80 headlight, the bumper cover must be partially removed, hence the labor charges.