Earlier quoted context omitted.
Your estimated costs are pretty average, but I found the €30k figure curious. Used cars are dirt cheap in Germany, and they are often in really good shape and well maintained compared to used cars in other countries. I occasionally drive a 20 year old Opel that was purchased 7 years ago for €2500. It works great. I ride my bike most of the time, but it's really handy to have a car to haul kids or heavy/bulky stuff.
€30k is only a little under the annual salary in Germany, so I'm suspicious that this figure is somewhat overblown as well. €30k is enough for pretty much any new entry level or basic trim car outside of Audi/BMW/Porsche.
Cars are important status symbols in Germany, and people who can afford it often do exactly as described--buy a new or slightly used Audi/BMW/Mercedes, use it for a while, keep it in absolutely immaculate condition, and sell it on a couple of years later for close to what they paid for it. Those higher end cars often go through many owners until they no longer pass inspection and finally get exported. 'Ordinary' people are more likely to drive lower end cars, which seem to have a different life cycle, ending as student cars and getting crushed instead of exported. That's my impression anyway, could be wrong. My experience (see Opel reference above) is that those lower end cars can be had for pretty cheap and often in great shape. With a little care, you can keep them running for ages on the cheap.