you forgot to add the tax to the ticket

Once you add the tax to the tickets, the $360 fare from Air France would be $560 ...

LH (Luthansa) is notorious for that. Their tax and fuel surcharges are outrageous.

I dont intend to go to a lot of cities - that is not our first trip to Europe ... Nor take the train ... too much time, too restricted by the train schedule.

We always rent a car if we have more than a week and leave the city.

FWIW, we have done a full month camping trip in Europe quite a number of years ago. Basically cross the channel from Dover to Calais - to the North we covered as far as Sweden, to the South we covered Spain, and all the countries in between. But we did not go to Eastern Europe.