Money
Compared to other European countries, the cost of living in Germany is relatively low.
Rent, which varies significantly from city to city, accounts for the largest portion of expenditure. In smaller cities you can often get by with less money. But some big cities are more expensive than others. For example, people living in Munich, Stuttgart, Berlin, Hamburg and Frankfurt am Main will have to budget for considerably more rent than those in Erfurt or Saarbrücken, for example.
Find more information about some differences between cities: studying-in-germany.org/cost-of-living-in-germany/.
Take a look at the EURES Portal to get an idea of the average of the various prices in Germany.