I suppose it's the nearest thing to a new E86 you're going to find, but it's still approaching 20 years old so some rubber and plastic parts are still going to need replacing - probably including the tyres.
The problem is if you use it the value will plummet as mileage goes up, and if you don't use it you've bought an ornament!
Whilst the tyres may well need replacing due to age...this is no different or more expensive than replacing any other tyres which is an inevitability of any car ownership.
People often talk about "rubbers and plastics" needing replacing. Again, this is no more than, and in fact in all probability less, than any other car of a similar age that has been actually used and exposed to the elements.
They oft talk about things like A/C rubbrr seals. My E31 840Ci, with only 28K mikes on the clock and driven only 3K miles in over 20 years - most stored in a dry garage - only eventually lost its refrigerant not because of leaking seals but a hole in the condenser!
Exposure to the elements, weather and heating/cooling cycles do far more damage to rubber and plastic components.
Whilst the value of that car is related to its mileage and would suffer dramatically if significant miles were put on it, there is absolutely no getting away from the fact that mileage is a HUGE determinant in the 'classic' car market.
However well-maintained a high mileage car is, what can never be undone (legally anyway) is the mileage!
Miles put wear and signs of wear on everything! Engines, suspension parts...albeit those things can be correct - at a cost. Also, paint, light lenses etc inevitably show wear on a high mileage car. The wear on things like trim, seat cushions sagging, leather stretching etc are far more difficult to correct.
Yes, there is an element of "you've bought an ornament." But, people buy paintings and sculptures etc. People want different things.
I'm not saying that I necessarily think this car is a 'good investment' because generally, unless you get lucky, I believe cars make for 'bad and unreliable investments'. However, nor would I say that particular car was a 'bad buy' for whoever the person who bought it is.
I can understand it.