To estimate the price of the 2021 Mercedes S500 S500 Standard with 75000 km mileage, I considered the listed prices of similar cars. The closest match is a 2021 Mercedes S500 S500 Standard with the same mileage listed for AED 329750. Another 2021 Mercedes S500 4-Matic with 22500 km is listed for AED 439000, and a 2023 model with very low mileage is listed for AED 599000. Given the significant mileage difference and the fact that listed prices are generally higher than selling prices, I adjusted the estimate downwards from the AED 329750 listing to account for market conditions and potential negotiation room.