To estimate the price of the 2018 Kia Optima EX (Base) with 137000 km mileage, I first looked at the selling prices of similar cars. The 2017 Kia Optima EX (Top) with 105800 km sold for AED 50000 on 2023-10-05. The 2016 Kia Optima EX (Top) with 198950 km sold for AED 27500 on 2024-07-18 and 2024-08-12. These prices suggest a depreciation trend. Next, I considered the listed prices of similar cars. The 2018 Kia Optima EX (Base) with 137000 km was listed for AED 32000. Other relevant listings include a 2017 Kia Optima EX (Base) with 140600 km listed for AED 33500 and a 2016 Kia Optima EX (Base) with 143000 km listed for AED 29000. Given the condition and mileage of the target car, I adjusted the estimate slightly lower than the average of these listings to account for negotiation and market conditions.