To estimate the price of the 2018 Mercedes E400 V6 3.0L Twin Turbo convertible with 64000 km mileage, I considered the listed prices of similar cars. The closest match is the 2017 Mercedes E400 V6 3.0L convertible with 30000 km listed for SAR 175000. Given the 2018 model year and lower mileage, the target car should be valued higher. The 2017 sedan variants with higher mileage are listed between SAR 112500 and SAR 175000. Considering the convertible body type and lower mileage, I adjusted the price upwards. Factoring in the car's good condition and GCC specs, I estimated the market price accordingly.