To estimate the price of the 2016 Mercedes S400 V6 3.0L Twin Turbo with 126000 km mileage, I first looked at the actual selling prices of similar cars. One sold for 164500 SAR with 133000 km on 2024-03-12, and another sold for 164000 SAR with 115000 km on 2024-04-27. These prices are very close, indicating a stable market value around 164000 SAR. Next, I considered the listed prices of similar cars. The closest match in terms of mileage and condition is listed for 160000 SAR but not delisted, suggesting it hasn't sold yet. Other listings range from 150000 to 190001 SAR, with most delisted prices around 150000 to 170000 SAR. Given the car's good condition and similar mileage to the sold cars, I estimate the market price to be slightly lower than the recent selling prices due to the car's higher mileage compared to the 115000 km car that sold for 164000 SAR.