Air fare fluctuates greatly. There is no way to predict at this point the air fare cost. Waiting until the last minute for high season tickets to Europe can be a mistake. As far as other expenses, Munich is not a cheap place to live, but with a little planning, you can spend your summer there without too much damage to your checkbook, depending of course on your lifestyle. It really depends on you.
Most people spend money when they travel to other countries.
Depending on which you choose, this will save you time and money if you plan to travel. If you are under 26, you can get extra savings with these passes as well. Following is a conservative budget for a 50 day stay in Munich. Keep in mind that this is based on getting your air ticket early and cutting down on daily expenses. It is a student budget.