Just one observation on looking at the picture. Just to be safe, not meant as a criticism of the car or seller etc.
The front discs have some markings on them. I guess it could be down to aggressive cleaning or resting up for a while? You can see where the disc has been against the pad. Do make certain you have checked the brake fluid level in case it has been garaged and a small leak has occurred? Then give them a couple of firm stops to clean off the surface once they are warm through. That should clean them up and allow you to see if there are any concerns.