To estimate the price of the 2019 Audi A5 40 TFSI S-Line I4 2.0L Turbocharged 40 TFSI Design (Top) with 100000 km mileage, I considered the following data points: 1) A similar car with the same variant but lower mileage (40000 km) sold for SAR 150000 on 2023-09-23. Adjusting for the higher mileage, the value would decrease. 2) Another similar car with the same variant but lower mileage (47000 km) is listed for SAR 127000. Adjusting for the higher mileage, the value would decrease. 3) A similar car with the same variant and exact mileage (100000 km) is listed for SAR 135000. Considering the listed price is usually higher than the selling price, the actual value would be lower. 4) A similar car with the same variant but higher mileage (185000 km) is listed for SAR 90000. Adjusting for the lower mileage, the value would increase. Based on these data points, I estimated the market price by averaging the adjusted values.