To estimate the price of the 2015 Kia Carnival V6 3.5L GDI L (Base) with 280000 km mileage, I first considered the selling price of a similar 2017 Kia Carnival V6 3.3L GDI EX (Mid) with 178000 km mileage, which sold for SAR 37000 in April 2024. Given the older model year and higher mileage of the target car, I adjusted the price downwards. Next, I looked at listed prices of similar cars: a 2015 Kia Carnival V6 3.5L with the same mileage listed for SAR 27000, and a 2016 model with higher mileage listed for SAR 32500. Considering the target car's average condition and the fact that listed prices are generally higher than selling prices, I estimated a price slightly lower than the lowest listed price but higher than the selling price of the newer model with lower mileage.