To estimate the price of the 2019 Nissan Sunny I4 1.5L S A/T (Base) with 123000 km mileage, I first looked at the selling prices of similar cars. The closest match is a 2019 Nissan Sunny I4 1.5L S A/T (Base) with 130000 km sold for 25000 SAR on 2024-05-08. Another relevant data point is a 2020 model with 72000 km sold for 36500 SAR on 2023-12-27, but this car has a lower mileage and is a year newer. The 2021 models with 1.6L engines sold for higher prices, but they are not directly comparable due to the different engine size and newer model year. The listed prices for similar cars range from 26500 to 36500 SAR, but these are generally higher than actual selling prices. Considering the selling price of the most similar car (25000 SAR) and adjusting slightly for the mileage difference, I estimate the market price to be slightly lower.