Financing plan single-family house 150sqm

I might be a bit old-fashioned, so such sums and the associated levels of debt and terms are simply too high. I am not writing on any kind of reason, but this would be the rough direction.

I lived in Nuremberg for many years and we also wanted a house. There was almost nothing to find. No plots either. Although prices were much cheaper 15 years ago. The supply was already very tight back then. We both had good jobs and earned well. However, we also had a cheap rental apartment.

But we still wanted a house.

And so we came to Saxony-Anhalt. Not far from Erfurt, Weimar, Jena. The plots and houses were almost free.
And so the choice was a house in Nuremberg for a lot of money and debt or a house in Saxony-Anhalt for almost no money. Especially since this one was also significantly better in terms of location and the plot. So we bought in Saxony-Anhalt. Went there every weekend and renovated, remodeled, etc. all without credit.

Then we bought a rental house in a nearby district town for 60,000€ at the time, 10 apartments and a rental yield of 40%! Took a small financing for that, now paid off.
Could have also been financed with equity.

We gave up our jobs, my wife is at home and takes care of the rental house and our child. I found a great job. Everything is paid off and we are happy to have taken this step. An important criterion was a fast internet connection. We have had VDSL for many years now. And today it totally doesn’t matter whether I order something in Hamburg or Halle.

From time to time we still drive to Nuremberg, it’s 250 km on the highway. I no longer have long ways to work, don’t stand in traffic jams daily, and everything fits.
Do you have to work for the bank all your life then? I think no.

Regarding children, one has to say that it is worlds better here in East Germany than in the West. Our daughter attends a private school here and it is simply great.
15 children and 2 teachers in one class, swimming pool, medical service and everything new and clean. I would not have believed it possible.

Building land here still costs between 40-60 euros. Sometimes only 20€.

I just wanted to show some perspective.

That's nice. Everything worked out well for you. Having a lot of equity certainly helps, no doubt. But what are you trying to tell me and us with that? Should all prospective homebuilders now come to you in Saxony-Anhalt because it's cheaper there? Then in 3 years it will be just as expensive there as everywhere else.

And one more thing: I'm not working for the bank, but for my own four walls.

Not everyone can and wants to give up their job and social environment just to get homeownership cheaper.

So the buyer is paying off for 20 years now and still has €200,000 remaining debt. With an interest rate possibly only 5%, there were times in the mid-90s with 8% mortgage interest, what would the monthly rate then be?