What does Dinan cost to dealers? Looking to buy 750/ negotiate it in deal
 

Looking to buy a 2010 750Li xDrive from a local dealer. I've bought from them several times before with generally positive experiences.

Car is CPO with 54k miles, they are asking $53k. Seems a little high, but that is close to the KBB. Instead of working them on the price, I wanted to have them do the Dinan Stage 2. Anyone have any experience on this approach or know what the mark up usually is?

Thoughts and feedback much appreciated.