To estimate the price of the 2018 Mazda 3 R (Top) with 100,000 km mileage, I first looked at the selling prices of similar cars. The closest match is the 2016 Mazda 3 R (Top) with 77,300 km sold for 43,500 SAR in February 2024. Another 2016 Mazda 3 R (Top) with 125,000 km sold for 32,500 SAR in March 2024. A 2016 Mazda 3 R (Top) with 155,500 km sold for 37,500 SAR in April 2024. Considering the 2018 model is newer by 2 years, I adjusted the price upwards. The listed prices of similar cars also provide context: a 2016 Mazda 3 R (Top) with 77,300 km was listed for 43,500 SAR, and another with 125,000 km was listed for 33,000 SAR. Given the 2018 model's newer age and lower mileage, I estimated a higher price. Factoring in depreciation and market trends, I arrived at the final estimate.