Given the lack of specific data points such as selling prices, offers accepted, and listed prices of similar cars, I will use the new car price and apply depreciation logic. Assuming a new 2018 Mercedes E400 V6 3.0L Twin Turbo Standard coupe was priced at around 300,000 SAR, and considering a depreciation rate of 10% per year, the car would depreciate approximately 30,000 SAR per year. Over 6 years (2018 to 2024), the total depreciation would be 180,000 SAR. Therefore, the estimated price would be 300,000 SAR - 180,000 SAR = 120,000 SAR.