I don’t like to do it, but the OP is somewhat right.
Of course, it makes sense to talk to the people. Whether architect or builder. He probably wants to clarify the HOW right now. However, the question about the shell construction costs or the stone is simply wrong, too early. Most people in the forum have dealt with many companies. Some even created Excel sheets for every comparison detail. We are probably among the exceptions (3 architects, 1 prefab provider -> in the end assigned the work ourselves without an architect and the house is standing )
You set the budget! Whether Kfw 70 or passive house as well. Architect means that in case of doubt there is no cost certainty (he has to tender himself first or you tender with his plans if you don’t want to pay him for these steps). Prefab house means that everything can be planned and priced from the beginning. But not everyone assigns individual trades themselves.
Well, whether architects will talk to you longer than 1 time 2 hours, you will have to find out yourself. In any case, you will learn something from every conversation – even if it is just that you should first exchange ideas about style and house type instead of immediately discussing the filling of the stone and that a "real" architect probably doesn’t just redraw your design neatly, but designs it himself. Drafting is done by the draftsmen, but they are not architects.
Well, be that as it may, you will still have to learn a lot despite everything and I also consider the chance very high that the conversations will not go the way you probably imagine them at the moment.