Avensis Kombi D4-D

Hello, I am currently driving a Volvo V40 1.8 petrol. The car has 150000kilometers and I have to travel because of the profession in the future about 30-35,000 Kilmoeter. That’s why I thought it was a diesel. I now have an offer about an Avensis diesel with 85KW. The car has already 81000km but is in a very good condition. The timing belt is still made and equipment he has e.g. electrically foldable mirrors, air conditioning, radio CD, on-board computer. Year of construction 2004 (new model) The whole for 15000.- Now I would be interested in what you think of the offer as professionals and what you say about the mileage? When I looked at the car today, an average consumption of 7.8 liters was on the on-board computer ! That already occurred to me a bit high or is this normal with the vehicle? Thank you already in advance. MfG Thorsten