Contracts signed - doubts within the withdrawal period

Especially with those, the boundaries blur. It depends on the engine and equipment. Btw, for all three, the chassis including engine and transmission is identical. The Octavia is longer and requires more sheet metal.

Platitudes and trivialities don't exactly reveal you as an expert either.

Car manufacturers calculate in 0.1 cent (!).

I cannot confirm that - I have worked in the automotive industry for years. Even whole cent amounts hardly matter, because you never recover the opportunity cost.

Mercedes sells a little over 2 million passenger cars per year. If they save 0.1 cent on even a small portion, it generates a profit increase of 2,000 euros - no one changes a contract or picks up the phone for that.

Quality does not always have to do with the price. I negotiated down from KfW 55 to KfW 40 without extra cost and additionally got a 3.5% discount as well as two extra roof windows and an additional terrace door + fireplace. Many negotiate when buying a car but not when buying a house. It is also difficult when you unconsciously signal to the seller that you are eager for the house and also mention the budget.

Again. No. The market is currently enormously driven by supply and demand. A craftsman or self-employed person with full order books inevitably calls different prices than someone who urgently needs orders at the moment.

And yet both must have done their calculations and no one sells themselves short. That there are extreme peaks upwards and downwards is not disputed by me, but these are, at a 95% confidence level, not the rule. Statistics simply do not lie.

Then comes a lot of hot air... it gets interesting here:

The production costs of the different manufacturers should differ by at most a single-digit euro amount, yet the car with the VW label is between 1000 and 2000 € (depending on the equipment variant) more expensive than the Seat, that is 10 - 20%.

Wonderful: 10% is the same price. Whether we are talking about €1.49 for fabric softener or €350,000 for a house. In this range, you get the same for the same. A house that costs 30% more or less will not be the same. Just as a Duster for €15,000 is not the same as an Audi Q3 for €30,000.

The models, brands, products are, by the way, almost* arbitrarily interchangeable.

*Exceptions prove the rule.

Car: a lot of industry, little craftsmanship; house exactly the other way around.

Of course: the cheap house will have cheaper tiles, cheaper windows, cheaper roof tiles, etc. (although that doesn't necessarily mean less durable, windows from PL are simply cheaper without being worse).
But the cheaper house can also be cheaper because those who make it are paid less than others. This explains how Winnetou in NO Brandenburg, Oderbruch, right near Siberia, builds the palace for little money, while Arifas, because there are no millions there either, has to settle for simple.

Prefab house sector: A Scanhaus Marlow from the HRO region is simply cheaper to produce than a Viebrockhaus. Even if you compare equal with equal.

Karsten

Viebrockhaus builds solid, not prefabricated. And depending on where you build, they charge different prices for the same houses.