Realistic cost framework?

I will never understand how potential builders can base their house construction exclusively on bare numerical data from providers...

I think, especially as beginners (as we are), you first want to get an overview of what is available for how much money or what the minimum is. In our specific case, it is mostly about drawing on the experiences of builders in order to learn to estimate all ancillary construction costs and to find out whether something essential has been overlooked.
We are fully aware that we still need to keep a reserve for all sorts of extras. But since we have no experience, we wanted to find out this way what one can roughly budget. It is not about the financing amount here but about a rough cost planning on which the project "house construction" stands or falls.

It may sound a bit naive at first glance, but you have to start somewhere. Especially since the definition of a "reasonable standard" is debatable.

Especially since the definition of "reasonable standard" is debatable

Not really

As you do, many potential builders first look at the price to be paid for a single-family house. In the next step, one or two conversations are held with the currently preferred provider. In these appointments, it quickly becomes clear what is meant by "reasonable standard," as well as what it costs to achieve it. In the next step, the "serious" ones in the industry are then found on their own.

Of course, exceptions also confirm the rule here; these exceptions are then found in forums that operate a moderated forum ... almost without exception.

Rhenish greetings