The most expensive thing in Germany is accommodation. It all depends on how much you'll pay for a room.
I'm currently living in Nürnberg. Renting an apartment for a single person costs on average 450-500 Euro. If you have luck, you can find something cheaper. But it's hard to find something for next month, I've searched for about 2 weeks (it is considered extra speed) and I've found an apartment available from 2 months later. You must note, that if you rent an apartment for a single person, it is written in the contract that you'll be living there alone!
When it comes to rooms in WG (Wohngemeinschaften - apartment communities) I haven't found many offers. Room costs about 300-350 Euro - I was surprised it's not much cheaper that renting an apartment. The problem is, you must be accepted by future flat-mates, and they choose from many offers, something like casting.
According to this German apartment website, apartments in Munich are about 50% more expensive. Of course those are only statistics, but they suggest that your chances of finding something cheap aren't high.
Generally, now in Germany we have an apartment crisis, and there were even student protests against the prices being out of reach of the average student (note, German student). You'll be really very lucky to get an accommodation in a dormitory, at least according to media.
When it comes to hostels, in Berlin they cost about 10 Euro, but Berlin is much cheaper than Bavaria. On the list from Ivan's answer there is only one hostel at this price. When it comes to kitchens, it depends. In Berlin you'll have a kitchen, in Nürnberg there was only the possibility of buying dinner (about 6 Euro). In that case you'll have to eat only cold dishes.
When it comes to food, it's not very expensive here, but you must buy in big shops such as Lidl, Aldi or Norma. A big can of soup (800g) cost from 80 cent to 2 Euro, depending on type, they are generally good :) Noodles cost 50-80 cent per 500g. Meat cost about 5-6 Euro/kg (the cheapest). Beer costs 40 cent per 0.5 l :) It is possible to spend 100 Euro or less monthly and still be far from being hungry.
Public transport is very expensive and if you don't have accommodation near the university you'll have to pay from 50 to 100 Euro. I've found this website with ticket price info. If it's similar to this in Nürnberg, the higher prices are when you are about 50km from Munich.
In conclusion, 500 Euro is very little for Germany. You could do it if you got a place to live for not more than 300 Euro. But it would be survival only anyway. You'll need also books etc., and those are expensive. And social life, and free time activities.