To estimate the price of the 2016 Audi A8 L 50 TFSI Quattro V6 3.0L Turbocharged 60 TFSI (Top) with 90000 km mileage, I considered several data points. First, I looked at the selling prices of similar cars. A 2014 Audi A8 V6 3.0L with 231500 km sold for 49500 SAR, a 2014 Audi A8 TFSI Quattro V8 4.0L with 116000 km sold for 72500 SAR, a 2016 Audi A8 V6 3.0L with 171000 km sold for 59500 SAR, a 2015 Audi A8 V6 3.0L with 81000 km sold for 89000 SAR, and a 2018 Audi A8 V6 3.0L with 104000 km sold for 160000 SAR. The most relevant comparison is the 2015 model with similar specs and mileage, which sold for 89000 SAR. Next, I reviewed the listed prices of similar cars. The prices ranged from 87500 SAR to 112500 SAR, with the most relevant being a 2016 model listed for 93500 SAR. Considering the selling prices and the listed prices, I estimated the market price by averaging the most relevant data points and adjusting for the car's condition and mileage.