To estimate the price of the 2019 Audi A6 55 TFSI Quattro S-Line V6 3.0L Twin Turbo, I first looked at the selling price of a 2020 Audi A6 45 TFSI Quattro I4 2.0L Turbocharged with 79800 km mileage, which sold for SAR 125000 on 2023-11-18. This car is a year newer and has a smaller engine, so the price of the 2019 model should be lower. Next, I considered the listed price of a similar 2019 Audi A6 55 TFSI Quattro S-Line V6 3.0L Twin Turbo with the same mileage of 122000 km, which was SAR 142000. Given that listed prices are generally higher than selling prices, I adjusted this downwards. I also noted the listed prices of other 2020 and 2021 models with different variants and mileages, which ranged from SAR 115500 to SAR 202000. Considering the depreciation and the specific variant and condition of the car in question, I estimated the market price accordingly.