The cost of living is relatively cheap in Berlin compared to other German and European cities. However, how much money you need depends on your personal life style. According to a study of the German student unions, German students spend on average 170 euro per month on food (basic groceries, i.e. not including eating out). In addition to the 170 euro, it is advisable to include enough money for cultural events, transportation and going out in your budget.
Further information on the cost of living in Berlin can be found here.
For more information on housing costs, please refer to the section on Accommodation.
You will find valuable tips about student life in Germany here.