Are performance phases 1-3 with the architect and lump sum offer somehow disadvantageous?

Reverse question: Why should I pay more when I obviously get the corresponding service on the market for less money?

That's why my question, what you expect. For an architect, this could be the talent refined during his studies to design a building (or even just his authorization to submit plans, for example if a landlord thinks he can charge the same price per square meter for a poorly laid-out apartment, and therefore the approval stamp suffices for him). An academic achievement at drug-dealing discount prices would be reason enough for me to initially suspect inferior talent, weakly motivated performance, or the like. I wouldn't buy a Rolex for fifty bucks, as it is probably fake if not stolen. One could talk about a Rollex, Rohlex, or Rolecks — then one could philosophize about "plagiarism" and probably exclude "stolen goods" ;-)

Counterquestion: Does the Rolex show the time better than a Gshock? Is the food at the discount store worse than elsewhere? Do you reach your destination better with a Porsche than with an Opel?

For standard houses, I don't need an architect expert. Besides, an expensive service is not necessarily better than a cheaper one. There are plenty of examples of this in the forum. I prefer to rely on experience.

For standard houses I don’t need an architect genius. Besides, an expensive service is not necessarily better than a cheaper one.

But a non-inferior service is rarely offered at a discount price; in your example, I would expect an architect who just barely made it through their studies. What would motivate a fully trained academic to provide a qualified service at a burger-flipper apprentice’s hourly wage? That’s why I mentioned the Rolex example, because they are only traded at bargain prices when they are fake or stolen — not because they are better. My last purchased watch was a Piratron for fourteen marks ninety-five, after that I still wore two promotional gifts; by now, the built-in clocks in my phone and in the Opel are enough for me (there’s probably one in my Porsche too, but it’s still at the dealer).

You did not understand. The Opel also has cheaper parts in it but gets you to the destination just like the Porsche.

What can I say. I was absolutely satisfied with the price-performance ratio. I just carried out the other trades the same way, everything went well too.

You didn't understand. The Opel also has cheaper parts inside but gets you to the destination just like the Porsche.

No, you didn't understand. I can't compare it to the Porsche yet, but I know from daily use that the Opel gets me to my destinations.

What can I say. Was absolutely satisfied with the price-performance ratio.

You haven't explicitly said it yet: was it the performance of a run-of-the-mill guy, or what was expected to be delivered by the architect ...

So I find this whole fuss with an architect for a single-family house totally exaggerated. There are thousands of floor plans on the internet and the structural engineering of a single-family house is not rocket science either. I prepared my building application myself and a friend who is a master carpenter signed it and that was that. Paid 630 euros in fees to the building authority and the construction could start.