I admit when I first looked at the invoice, the long list of items made me nervous. But, upon closer inspection, there are no part costs - only labor and paint. And the majority of the labor seems to be around buffing and paint retouching (if the invoice is to be believed).
If I were you, I'd inspect the exterior of the car very closely. If I am happy with the condition, I'd happily take the discount.
Oh and, I know many threads have mentioned the lack of difference b/w the various suspension settings. For me personally, I can DEFINITELY tell the difference. I experimented with various settings, and although I do enjoy the "soft" Ride Comfort, but it feels a bit "floaty" so my current setting is Ride Comfort to "firm" and Handling to "Sports".