My wife and I are doing some travel by train and I ask the question. How much more expensive will it be to just book the travel as we go vs booking before we leave the states?
We are only traveling from Frankfurt to Rothenberg to ULM to Munich.
After that, we will be getting a car and driving the APLS and black forest area.
You can answer that question yourself by going to bahn.de and pricing a ticket tomorrow and a ticket six months from now. And hopefully Lee will be along with better info. Often there are discounts ticket available on line, well in advance but there will be restrictions on changing and refunds of these advance sale tickets. Sometimes the saving can be significant.
It you look up those three routes through the Deutsche Bahn link at Looking Up Train Schedules and Routes Online, it will show both the lowest available Savings Fare for any travel date and the full FlexPreis Fare. Since most German tickets are now available to buy 6 months out, your travel dates may already be posted. I would not pre-purchase a Savings Fare if the departure from Frankfurt is straight from an international flight arrival, due to refund and exchange restrictions. See regional ticket offers summarized at https://www.ricksteves.com/travel-tips/transportation/trains/germany-rail-passes#ticket-tips and under Offers on the DB site.
When will you be traveling? The length of the period between purchase and travel is a big factor since prices rise as tickets sell.
If you buy the right day passes for regional train travel - at the station - the two of you can do those 3 legs for about €110 total. The Bayern/Bavaria ticket would be involved for those 3 trips; on trip #1, you'd need additional local RMV tickets to reach Bavaria (less than €20/2 from FRA.) The RMV is a local transit authority for the Frankfurt area. You won't find much if anything about it on Rick Steves or the DB website. Here's the webpage but it's somewhat impenetrable. Don't waste a lot of time on it. The idea is to just buy the RMV and Bayern Tickets from an airport station ticket machine and go.
You might want to reconsider the Black Forest by car. From Ulm you can get there cheaply by day pass, and once you're there, train travel around the entire BF is free of charge when you stay in a participating KONUS town. For details, click on the Konus flyer on the following page:
