Within a transit cooperation there are integrated fare systems, you pay for your whole journey at once at start, and in most cases there is one fare for one relation, no matter if you take the bus or the railway.
Most organisations encourage riders to buy weekly or monthly passes, which are comparatively cheap.
I am setting up a table containing the fares in several towns and cities, including Munich, Stuttgart, Frankfurt and many others. Ticket 2000 monthly pass transferable take a bike or a dog with you, without extra charge after 7pm and all day at weekends and holiday, up to two adults and three children may ride on it. Before you ride you must deduct your fare level, by counting the zones you travel through on the fare map.