a4inga

i've been told that it'll cost $540 to replace my oxygen sensors for an audi a4 2.8 quattro (50k mi). i've been quoted: $340 for parts (2x$170); $86.5/hr. for 2.3 hrs ($200). the book quotes 1.9 hrs, but he said the book does not include the drive-cycle that needs to be performed after the sensor are installed.

does that sound right?
any suggestions?
any way i can sneak them under the emissions warranty (8/80k)?