I am pretty good on the German rail buying, less so on France. We are doing a rental car switch from France to Germany- dropping a car off at the station in Metz, France and spending the night in Metz. The next morning, we will take the train to Saarbruecken, Germany and then picking-up another car, there (not at the HBF- but we can take a bus from the station to 500 meters away from the rental agency.)
So..my question is this- are there advance deals to be had on a train that goes from France to Germany or will I do just as well just buying the tickets the morning I leave? It will be me, and 3 girls (13, 7, and 4). Thank you!