To estimate the price of the 2018 Nissan X-Trail I4 2.5L S 2WD (5-Seater) (Base) with 228000 km mileage in average condition, I considered the following data points: 1. A similar car with the same variant and mileage sold for 45000 SAR on 2024-09-01. 2. Another similar car with the same variant but lower mileage (135000 km) sold for 40000 SAR on 2024-01-13. 3. A classified listing for the same variant and mileage is currently listed for 47500 SAR. Given the close match in variant, mileage, and condition, the most relevant data point is the car sold for 45000 SAR on 2024-09-01. Considering the slight depreciation and market trends, I adjusted the estimate accordingly.