After reading the post, I have to agree, these are currently the prices. I am even at a similar price for only 160sqm right now. One may perceive it as expensive, and it is, but it just won't get cheaper.
The perceived too expensive price is mainly because it was significantly cheaper 12 months ago plus the loan was free. It has developed sharply upwards in a very short time. Normally, such things take years/decades.
But it won't change anything, you keep paying or renting. And in 30 years it will be said, "oh good that I built when I see the prices now..." Just like the motto: Yesterday was better than today, and today is better than tomorrow.
I also regret not having built 4 or 5 years ago, with 1.2% loan and construction costs about 40% lower. But at that time my life just wasn't that far along. Building for owner-occupation depends on the course of life. You don't just build at 20 because it's cheap when you have no family, no job, etc. You build when you can and need to. Unfortunately, it is a bit more expensive right now. And the question is, does it have to be 170sqm or is less enough. Building generously is always a wish, but not a necessity ;-)