I have looked at newer ones numerous times, currently have a 911 GTS. There aren't any dealers close to me so that is my one big issue. I have just found a mechanic locally that is certified by Aston Martin so the wheels are turning a bit lately.
Like others have said cost of ownership of this type of luxury items is always subjective, that's why is a luxury. Sounds like you know the history and know it's been well maintained. I would get it to a dealer and it checked out, all cars that my have been sitting/stored may have little maintenance issues, spending a few $$ to know what you're getting into is money well spent. Little things like Z rate tires general maintaince cost a bit more if you're not used to it.
Aston builds a beautiful car and I'd bet it would put a smile on your face every time you drive it.
Best of luck and keep us posted.
