$400 difference. The question now is what is the value added for having a car. Anyone have any insight?
A car offers you an enormous amount of flexibility. I have traveled these routes many times over the years, even in a group of 6. I wouldn´t even consider your itinerary without a car. There is always advice about the difficulties driving in France, typically from those who have rarely done it or from those who have never driven in France.
Admittedly, driving now has its downside, myriad speed cameras and constantly changing speed limits. In the days of 50, 90, and 130 kph limits, knowing what speed should be maintained was very easy. Now the limit could be anything, but in spite of these concerns, a car fits your needs perfectly.
If you´re getting your train information quoted in dollars, you´re looking in the wrong place. All ticket prices should be in euros.