Age is just as hard on a car as mileage, so even at that low mileage, there are a lot of items that should have been replaced or will need to be replaced in the future. If I was going to pay full Kelley Blue Book Excellent Value Private Party Retail price (or more), the car would really have to be nearly perfect. I would require to have a full, complete, documented history with receipts of all maintenance and repairs. And I would need to take the service history with me if I bought the car. The owner should have replaced over time many items like rotors, possibly a radiator, V-belts, various radiator and heater hoses, etc.
Make sure that at minimum the brake fluid was replaced every two yeas and the radiator coolant every three years.
If anything of the above was missing or incomplete, I would surely not pay full KBB excellent private party value.
Also, cars always look perfect in digital photo's, so be sure to look at the car very closely.
Last, at that age, even with the low miles, I would expect that the timing chain guide rails would need replacement as well as the timing chain tensioner.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".