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 2012 Mercedes R300 V6 3.0L Twin Turbo Standard minivan had an approximate price of 300,000 SAR, and considering a depreciation rate of 10% per year, the car would depreciate as follows: 2013: 270,000 SAR, 2014: 243,000 SAR, 2015: 218,700 SAR, 2016: 196,830 SAR, 2017: 177,147 SAR, 2018: 159,432 SAR, 2019: 143,489 SAR, 2020: 129,140 SAR, 2021: 116,226 SAR, 2022: 104,603 SAR, 2023: 94,142 SAR, 2024: 84,728 SAR. Given the high mileage and average condition, I would further reduce the estimated price by around 20%, resulting in an estimated price of approximately 67,782 SAR.