What may ceiling spots (in new construction by general contractor) cost?

They can certainly keep up if you choose something reasonable, but that is usually never the most affordable option. Yes, there are also quite good retrofit solutions - see above - but for me, they have no place in a new building. Others may think differently.

They think differently even though they place special value on good lighting. Panels and stripes, in my opinion, cannot compete with beautiful lamps and should only be used discreetly as an accent.

That does not have to be contradictory, and I am not aiming to install just any panels everywhere, but there are now enough beautiful lamps that do without the crutch of lamp holders from the last millennium.

200€ would be too much for me!

We paid 50€ each for the cans in the concrete ceiling and the wiring, and I already thought that wasn’t exactly cheap...
I drilled the holes in the membrane myself, bought the spot frames and bulbs (GU10) online, and I will connect them myself as well. It’s really no rocket science.
We had a lighting consultation with an interior designer and came up with 35 spots. And they really are only in the hallways and accentuated in the living/dining/kitchen area. Over 40 is not that extreme, in my opinion.
Regards,

For the concrete-embedded Halox box including pulled-in cable by the electrician, we paid about 70 euros in 2019.