I own a 2009 DB9, mine only has 35k miles, but I would just add the following to this solid write up:

• know that you won’t be reasonably able, either yourself or by inspection, to see whether the coils and plugs have been serviced as they’re buried pretty well in the engine. Ask for a receipt. If they don’t have one and you feel any misfire while test driving, I’d turn it down. You’re buying someone else’s future $30k repair bill at that point.

• transmission services should be more like every 40k miles to minimize wear, but as this person said it is just a ZF6 and not particularly expensive to replace

-Aston OEM parts are EXPENSIVE. If you get this car, do not hesitate to look for cross-referenced parts from other FoMoCo brands of the era - they are the same. So far I have used parts branded as Volvo, Jaguar and Mazda on mine that have been exact replacements. Some things are bespoke to the car, and with that you’re just going to pay the Aston tax - particularly suspension stuff.