Construction costs are currently skyrocketing

... Only the question about the installation is still open?

I already addressed this question regarding our case on the previous pages. Certainly, this is not something that everyone can just do "easily".

That’s the crucial point. In the house price from the general contractor (GU), you already have amount X for the equipment and installation of the sanitary items included. Therefore, in the worst case, the additional costs can amount to the sum of the list prices (minus the reimbursement for the actual products). Surely you talked before pulling the trigger. How does the GU justify the additional costs?

The two bathrooms (6.5 & 12 m²) were budgeted at 7.5k for sanitary equipment including installation, so only the piping including fixtures. That I completely underestimated that this would not be nearly enough annoys me over and over again. But well, who already has everything meticulously on their radar at the first house build. I’m just the one who stumbled over the sanitary trade now.
The steep additional costs ultimately arise because the upselling mafia charges absolute sky-high prices for everything that does not correspond to the calculated standard (in my eyes). The general contractor of course has a great interest in keeping his house offer price "low" in order to appeal to the largest possible customer base. That he really placed no great value on the sanitary equipment in the offer, we all know now – including me. He does not have to justify that much: if we choose expensive things in the showroom, he simply passes the costs on to us, which is also understandable. The "problem" in my eyes here is the specialist sanitary dealer. That is known to be the most expensive store in town. Why our GU shops there specifically, I really can’t ask him :-D
But he also makes no move to leave this field to me now. The installations of the pipes remain with him, the installation of the peripherals including their purchase will be done by us, we have now agreed on that. He will still inform us about the equipment, but no large amount will come out of that. Nevertheless, we can now create our dream bathroom with a few thousand euros saved, and that is what counts at the end of the day.

You gave yourself the answer why the sanitary equipment suppliers are so expensive when you write that you have a dream bathroom. There is a demand that leads the sanitary trade to offer dream places and wellness oases and relaxation zones instead of wet rooms. :) Status symbols cost. In the past, it was the wall unit in the living room or the bedroom suite - now it is kitchens and bathrooms.

Oh yes, my parents' wall unit... I don't want to know how expensive it was. Today it's a case for bulky waste. Just like the Persian rugs. People used to happily spend a fortune on those.

You gave yourself the answer why sanitary equipment is so expensive when you say you have a dream bathroom. There is a demand that leads the sanitary trade to offer dream places and wellness oases and relaxation zones instead of wet cells. :) Status symbols cost. In the past, it was the wall unit in the living room or the bedroom suite - now it is kitchens and bathrooms.

We haven’t even planned a bathtub or chosen a steam shower, XXL bathroom mirror, etc. We currently shower in 80x80cm with a plastic curtain and in the future on 120x100cm level with the floor, that’s our dream. I thought that was already standard nowadays. However, I would immediately agree with you about the golden faucet with water symphony and 3D laser show. When it comes to fulfilling dreams, it also strongly depends on what kind of environment you are dreaming out of ;-)

The plumbers will come back down to earth again soon. I’ll just order what I like from Reuter online and get someone from MyHammer to screw it on, it’s really no rocket science.

The medics don't care. Only a few do it, and the Nachwuchs in their field is almost zero. The others are glad if even one comes who delivers and installs the clothes purchased from them.