To estimate the price of the 2012 Mercedes S350 V6 3.5L Turbocharged (LWB) Standard with 138000 km mileage, I considered the listed prices of similar cars. The first car with 149000 km is listed for SAR 69000, the second car with 167000 km is listed for SAR 48000, and the third car with 203500 km is listed for SAR 70000. Given that the car in question has lower mileage than all the listed cars, it should be valued slightly higher than the lowest listed price but lower than the highest. Considering the condition and mileage, I estimated the price to be around SAR 62000.