To estimate the price of the 2021 Chevrolet Spark I4 1.4L LT (Base) with 51000 km mileage, I first looked at the selling prices of similar cars. The 2019 model with 120500 km sold for 26000 SAR, the 2020 model with 34000 km sold for 31500 SAR, and another 2020 model with 94000 km sold for 26250 SAR. Given the average condition of the target car, I considered the 2020 model with 34000 km as the closest match, adjusting slightly for the higher mileage of the target car. Next, I reviewed the listed prices of similar 2021 models, which ranged from 28500 SAR to 37000 SAR. The most relevant listings were around 37000 SAR but considering these are listed prices, I adjusted downwards. Combining these data points, I arrived at a reasonable market price estimate.