To estimate the price of the 2020 Hyundai Elantra I4 2.0L Smart (Base) with 150,000 km mileage, I first looked at the selling prices of similar cars. The closest match is the 2020 Hyundai Elantra I4 2.0L GLS (Top) with 103,000 km sold for 64,500 SAR on 2024-04-17. Given that the GLS (Top) variant is higher than the Smart (Base), the price should be lower. Another relevant data point is the 2021 Hyundai Elantra I4 2.0L GL (Mid) with 104,000 km sold for 47,500 SAR on 2024-06-29. Considering the higher mileage of the target car, the price should be adjusted downwards. The listed prices of similar cars range from 48,500 SAR to 57,500 SAR, but these are generally higher than actual selling prices. Therefore, considering the depreciation and the condition of the car, I estimate the market price accordingly.