Thank you already for your answers!
The prices here are indeed still comparatively moderate. I don’t have a final price yet, but the same developer sold a fully basemented end-terrace house in the same city for €310,000 just a few months ago, and the same semi-detached house model in a more expensive neighboring city for €360,000. Of course, prices are continuing to rise, but we are quite optimistic that our calculations are relatively accurate. However, I am also calculating with around €350,000.