I started by looking at the selling prices of similar cars. The most relevant is the 2015 Mercedes G63 AMG V8 5.5L BiTurbo with 171000 km sold for 175000 SAR in April 2024. This car is very similar in year, model, and mileage to the target car. Another relevant data point is the 2013 model with 100000 km sold for 224000 SAR in May 2024, but it is older and has less mileage. The 2017 model with 73000 km sold for 350000 SAR in October 2023, but it is newer and has much lower mileage. The listed prices show a 2015 model with 171000 km listed for 189000 SAR, which was delisted in April 2024, indicating it might have sold for less. Considering the target car's mileage of 177500 km and good condition, I estimate its market price slightly lower than the 175000 SAR selling price due to higher mileage and the time elapsed since the last sale.