To estimate the price of the 2017 Mercedes E300 I4 2.0L Turbocharged Standard with 90000 miles, I first considered the selling prices of similar cars. A similar car with 68000 miles and Top variant sold for 100000 SAR, and another with 82000 miles and Standard variant sold for 117000 SAR. The car in question has higher mileage and is in average condition, so its value should be lower than 117000 SAR. Next, I looked at listed prices: a similar car with 84000 miles was listed for 123000 SAR, and another with 82000 miles for 120000 SAR. These listings suggest a market value slightly above 100000 SAR. Considering the higher mileage and average condition, I adjusted the estimate downward from the 117000 SAR selling price of a similar car in good condition.