I don't think you should be afraid of this car. Granted, the mileage might be "high" relative to some of its peers, but it is still approximately <6k miles per year, so consider that relative to another car.
You might want an estimate on "paint correction" services - sometimes they can run $1k - $1.5k for the cosmetic stuff. If the seller is willing to work with you on the "worn out" parts, then take the car seriously.
Also, with regard to the depreciation, remember you're being given the up front discount on the sale price. If we assume these cars are going to depreciate about $6-$8k per year, then you may still be OK. If you buy in the $1-teens-k, you'll probably end up selling it close to $100k, depending on your term.
If you plan to drive it, don't be afraid of the miles. If you are looking at this as a collectible (which it wouldn't really be - the F430 production numbers will see to that), then you need to up your budget and be willing to part with the dough.
If you're serious, run it through a thorough PPI and see what comes back. If the deal is still palatable, buy it, drive it, and smile like a crazy person!