Purchase advice Audi Cabrio wanted…

Hello, actually come from the golf forum, but since my mam would like to exchange her Escort Cabrio into an Audi 80 convertible I would like to have your opinion. The car is from an Audi dealer with new Insp., Tüv/Au, 4 new tires and 1 year warranty. 2.6 liter 150 hp dark grey sports seats with fabric built in 1994 66,000 km 2. h electric. deck 15″ aluminium (newly matured) seat heating wood decor radio with changer sport leather steering wheel More I know just net… Very well maintained. 8500,- incl. all. I found it expensive, but at DAT I found a dealer-EK of about 6800,-. Then there are the extras. Then the price is almost right! What do you think, is that ok? What my mother would still be interested in is what the 2.6 is used up. Do you get there with 10 liters? Thanks already for the answers….