It was $350 installed, although it looks like they charged way too much for the part, but not a lot for the labor:
“Corrections: Harness - Wheel Speed Sensor - Rear - LH
Requested log set to perform diagnosis. Alert was triggered by an internal fault within the left rear wheel speed sensor. Removed and replaced wheel sensor and test drove vehicle. Verified no alert is present.
Parts Replaced or Added”
Hub Unit (KMI 15 ABS Sensor) (2002218) $281.74
CLIP PAB COVER (2001315) $3.36 (they needed 4 of these)