Had an o2 sensor go out (used computer codes to sh...

Had an o2 sensor go out (used computer codes to show error). Called ahead of time to see what the estimated repair cost would be for an o2 sensor. Told him Vin number, mileage and year of vehicle. He said the estimated is usually around 250-300. Called another vw dealership and was immediately told o2 sensor are under warranty until 80k miles and if that is what the issue was it would be 0.00. Took it there and it was indeed covered and 0.00