A BahnCard 25 gives you 25% off journeys, can be combined with saving offers and costs ~60€ per year. A BahnCard 50 gives you 50% off journeys but cannot be combined with savings. I think it costs ~200€ per year. A BahnCard 100 gives you 100% off journeys, i.e. the only extra cost a journay may occur are either seat reservation costs or the "Sprinter" extra for the fast train Frankfurt<->Berlin, which is not included (and technically a seat reservation anyway). This option costs ~3600€ per year or some such.

The point is, if you want to take the train, either book ahead (and maybe get a BahnCard 25), or get one of the other two. I used to do a mere 2h journey a bunch of times a year (as returns), and the BahnCard 50 easily paid for itself in just 2 or 3 trips, while also offering fantastic flexibility, since it's always 50% off the regular price, which is static.

That's how people afford trains. Also, with the BahnCards, you usually get a free ticket for central public transport zones at your destination, for example for Zone A in Berlin.

Just for your example, a single from Munich->Berlin costs 65€ with a BahnCard 50, i.e. 130€ return, booked right now. The booked ticket lets you ride at any time within the next two days, so you are also not tied to a specific train and it's no big deal if you arrive later at the station etc. (which is not the case for special offers, which tie you to a specific train). 130€ return from München Hbf to Berlin Hbf is really not that bad.

Great advice .. I used my DB50 card for many years to do weekend trips all over that part of Europe from the Ruhr area (okay, mostly to Amsterdam, I admit), and it was definitely a good investment.

That was my impression as a tourist. I loved the German train system, but I couldn't afford to travel like that on a regular basis.

When I lived in Germany I just purchased myself a DB card, which cost at the time about 200Eu and gave me so many discounts on train-rides it paid for itself in a month. I was very happy to see Germany by train - very comfortable, fast, efficient, clean trains with a beautiful country rolling by outside .. not so in England, where I have had the worst rides in my life on crappy, unmaintained, overcrowded trains run by rude conductors and full of unhappy people. Was really shocking, to be honest ..