identical cars different market values

there has to be something different, even the color of the interior makes the price change on the S-class, for example, the Orange-ish color is known as Buffalo leather and at the factory increases the value by $5,000. and yes mileage plays a part as well, so they may seem identical, but i assure you I can find the difference, wheels/sport package? show me the listings...

The market value varies in different parts of the country too.

Also, there could be a difference in options. Distronic cruise control, rear seat package (split pwr seat, rear a/c ), designo Pkg, AMG Sport Pkg, are a few options that usually increase the value, though there are other options available that were pricey when new, like Comfort front seats, adaptive front seats, heated steering wheel, wood trim pkg, parktronic, side window shades aren't usually counted when the value is calculated by KBB, NADA etc