cost to replace brakes? on 2008 BMW 535xi

What is the cost, and when will it likely be necessary?

Asked by for the 2008 BMW 535xi
Please be aware next time of the "estimate" tab at the top of the site before proceeding.

http://repairpal.com/estimator

Estimate Includes:
Labor: $198 - $253
Parts:
$370 - $432
* Front Brake Pad Set
* 2 Front Brake Rotors