毎日ドイツ国内を動き廻るのならGermanrailpassかDeutschland pass

//www.bahn.com/i/view/GBR/en/prices/germany/germanrailpass.shtml
//www.bahn.de/micro/view/deutschlandpass/index.shtml
10日くらいになると後者のほうがお得になるようです。

10 days
Second class adult
320.00

Deutschland Pass 1 Person
299,00 EUR
こちらは一か月ですので・・。
ただし、夜行は不可。
船も不可です。

パス（Germanrailpass）が使えるか否かは、
//www.diebefoerderer.de/uploads/media/SCIC_-_Passangebote.pdf
Geltungsbereichをご覧あれ。

国を跨ぐ場合は国境までなので、
German Rail Pass Extension

Discover Germany and the best of Europe with the German Rail Pass Extension!
Enhance your German Rail Pass with this coupon and travel to Brussels, Prague,
cities in Austria and Italy on selected trains!

The German Rail Pass Extension is coming at 39 euros in 2nd class and 69 euros
in 1st class!

残念ながらフランスは入っていません。
Enhance your German Rail Pass with this extension coupon and travel to
- Brussels with the ICE International,
- Prague with the DB Expressbus from Munich and Nuremberg,
- Austria (Kufstein and Innsbruck) on DB-ÖBB Eurocity trains and
- Italy (Bolzano/Bozen, Verona, Bologna and Venice) on DB-ÖBB Eurocity trains!

This comes at only 39 euros in 2nd and 69 euros in 1st class!
For example: A German Rail Pass 3 days 2nd class (183 euros) together with the Extension (39 euros) comes at 222 euros only!

Mannheim Hbf-PARISをSparangeboteで買う方が安くつきませんか？
パスはドイツ国内に限り、外に出るときは、往復のSparangebote 118,00 EURとかで。