I live in Berlin too...

I'm not very careful with what I buy. If you cook from scratch, it's really cheap. You don't have to change your diet or anything.

Snacks can be a bit more expensive, but it's still (literal) peanuts in the budget.

I do shop at Lidl, and I do pick the store brand most of the time. However, I don't consciously try to save money on groceries. Good food is good living.

€5 gets me a typical breakfast with a little to spare. Coffee is around 75c per cup * 2 (good beans and oat milk). Avocado is €1 and 3 eggs also €1. That's already €3.50. Then add some olive oil prob just 20c but it adds up and maybe some dark chocolate and you're close to €4 already.

Should be easy to eat it then ;)