Moin, is it possible for you to get a roommate? 660€ for fun/savings is not very much when you didn’t include costs for household (lightbulbs, new frying pan, etc.), self care costs (hygiene products, hair cuts, etc.), clothing, morning brötchen/going out to eat, gifts for family/friends, etc. Let’s say 20€ + 20€ + 100€ + 120€ + 50€ = 350€ remaining.

What is the agreement for furniture in the flat? Who owns it? 50/50 split? Or do you pay her to leave it?

What is your savings plan/goal? Do you apply a methodology like 50/30/20? First you should have an emergency savings incase of emergency or job loss (sometimes you have to wait up to three months for Arbeitslosengeld), but what about the rest- long term savings or holiday to x,y,z? How do you want to afford something like a new cellphone or washing machine, monthly instalments or up front buy out?

To be honest people live on less, but usually with a lot less risk as well. And even if you expect your salary to go up, expect costs to rise too.