Yeah my cousin was in that type of a situation as well. He had the budget for an A5 1.4T 2017-2018 but after getting to know the maintenance cost, he backed off. If you're talking about the 2013-2015 models, those have excessive oil eating issues in A4 and A5, not aware of A3 though. A3 also has cramped space in that back with less legroom compared to Civic. Look for their common issues on internet and then check the car from authorized centre so that it's good to go. Also make yourself aware of the spare parts prices both maintenance and bodyparts etc so that you have a clear image of what you're getting into.
Civic is pretty overpriced and that 5.5-6.5M figure for Civic isn't digestible at all. Other options in this price bracket may also include W204 Facelifted C-Class 2012-2014 with more cabin space and more features as well.
