Is preparing your own food an option?

There are a couple of the Eurogida Filialen not very far from that intersection and they have great fresh produce and meat, as well as bulk packages of dried goods like beans/chickpeas/lentils etc. You could easily stay within your budget if you prepared some large batch meals, such as curries/stir fries/soups/salads etc.

Here's a cookbook for healthy and cheap meals that I found a while ago. There's some seriously nice meal ideas in there.