Given the lack of specific data points such as selling prices, offers accepted, and listed prices of similar cars, I will use the new car price and apply depreciation logic. Assuming a new 2018 Infiniti QX30 I4 2.0L Turbo Charged Luxe (Mid) was priced at around 150,000 SAR, and considering a depreciation rate of 10% per year, the car would depreciate approximately 15,000 SAR per year. Over 6 years (2018 to 2024), the total depreciation would be 90,000 SAR. Therefore, the estimated price would be 150,000 SAR - 90,000 SAR = 60,000 SAR. Additionally, the high mileage (178,000 km) and average condition would further reduce the value by approximately 10,000 SAR, leading to a final estimate.