Help needed - DBS ceramic brake replacement

[Scooby P1]

My father's DBS volante was found to have a small stone jammed in the rear caliper which has scored the disc so that 'according to Aston' it is now structurally unsound.

Their quote for a replacement pair of rear ceramic discs was a mind blowing £6.5k.

Anyone know of a cheaper way of doing this?

Appreciate your input. Cheers.

[Scooby P1]

Picture to follow as I am really sceptical of how much damage a stone can have done.
Plus, this particular DBS never gets driven in anger so is it really going to be a problem?

Amused by the part exchange comment!

Let me get a pic of the offending disc.