I am writing this from my room in Wiehre right now, for which I pay 300 euro per month. Ok, it's a room in a flat I share with 3 flatmates, not everybody wants to live like this, but still, even Wiehre and Herdern are hardly quarters only for the super rich.

Additionally Freiburg is so small that you can be pretty much anywhere within 15 minutes by bike, it really does not matter so much which quarter you live in.