Districts in Berlin are varied. Generally speaking, a buyer often has better yields in areas such as Wedding, Neuköln or other areas which are central, like Spandau, Reinickendorf. The areas which are considered "preferred" are Prenzlauer Berg, Mitte, Charlottenburg, Wilmersdorf, but there are some other really nice areas like Steglitz which foriegn investors have never really heard much of...
Remember Mortgages are hard to get in Germany. Normally they will be 50000 euros minimum lending & 60% loan to value could be your maximum.
Please keep in mind that you will have additional buying costs:
4.5% property tax, approx. 2% notary costs + the agent fees which can be 6% of the purchase price plus tax; (7.14%)
Donna Cohn- Harrison Stone International's partner based in Berlin for 30 years speaking English & fluent German.
The Areas of Berlin- CLICK HERE