Backfilling or basement construction?

One should also take a little look at the locations. Between Saarland and Rhein-Main, the prices are likely to be just a tiny bit different.

Sure, but primarily when it comes to the land costs. The material probably costs almost the same and the craftsman is not much more expensive either...

I wouldn't say that - the material and labor costs do vary noticeably across the country.

The material comes from the wholesaler and is probably more different in price from company to company than region-dependent. Craftsmen are certainly cheaper at the Polish border than in Munich, but it should not make more than a 20% difference...

You can take a look at the price lists of the different companies, there are big differences.

As mentioned, with Town & Country the difference for a turnkey house, I mean 169,000 to 200,000 in comparison Görlitz to Munich, so less than 20% for the entire house. However, I estimate the land prices to be 10 to 20 times higher, depending on the location. In this respect, the region mainly determines the price through the land costs...