Is building a house on a low budget still possible with the current prices?

In the years before I built, I wrote down every solid construction in the area and then after 1-2 years drove by, rang the bell, and asked how satisfied they were after experiencing all seasons. Here in the settlement, there was also a construction project where two single-family houses were built on one plot by Town & Country. When asked about their satisfaction, both reacted extremely differently, with the satisfied resident visiting the construction site daily and the dissatisfied one for the first time at the key handover. I then at least kept Town & Country in the selection but in the end opted for a local general contractor.

Build only the house you need - 150sqm, double garage, upscale finishes, finished outdoor areas, pantry, etc. are "luxury." But really necessary? Nope.

I agree.

What I can highly recommend is a study from which you can directly see the street

What I particularly appreciate with kids is a large hallway/vestibule, a spacious eat-in kitchen, and a sufficiently large pantry.

What I can recommend: don’t get fixated on nice-to-haves!
It already starts with where a study should/could dominate a house design. Free yourselves from these good pieces of advice, because I can tell you: then comes the children’s bathroom, the walk-in closet, a house makes no sense at all without a pantry, a basement of course, and without a walk-in closet, there’s no need to build more.
Also, the nationwide companies are named here now, but one knows that many REGIONAL (not nationwide) companies offer better conditions. Working with regional companies often makes it difficult to exclude entire trades. With regional ones, you have more options.

Here, the nationwide companies are named, where it is known that many REGIONAL (not nationwide) offer better conditions. Thus, working together and excluding an entire trade is often difficult. With regional ones, you have more options.

We compared and also visited the prefab house center in Heßdorf; for us, it became the regional company with very good conditions. Especially if you are confident to do some work yourself, you can coordinate trades individually and do not have to buy a package like "technical completion," "shell house," etc. For example, use your own electrician and still get plumbing through the company.