Your earthworks mean a foundation slab on a level, uncomplicated plot. They can increase significantly depending on the plot and especially with a basement.
Here (and with other pattern works + plumbing) lie the real differences buried and not in supposed huge regional differences. I alone spent more per room for the above item without feeling like I was in the luxury segment. It is simply a different standard. And while some wouldn't even accept some things in a rental apartment, for others it seems to belong in the dream house.
But you can't really see that as representative for such calculations. I don't believe the majority (and from them we want to get an average price). And I think very few spend 5000 euros on flooring and painting for one room, just on materials.
I completely agree with you... what always bothers me here in the forum is that people immediately write about "impossibility" and "this can't work." It does work if you stick to your own guidelines... and the flooring for €11.99/sqm doesn't necessarily have to be worse than the one for €50/sqm or even more. We are definitely very satisfied.
And the fact that our earthworks are so low is obviously due to the property... and it is also clear that costs for earthworks can be very flexible upwards... but you have to look at each property individually and you can't make any general statements either.
So I also shop in the specialty store.
Half the house is already tiled according to the construction service description, with partial numbering,
about 2000 EUR, the rest will be cork flooring and parquet, also about 2700 EUR (approx. 40 EUR per sqm)
Then comes putty and paint, about 1200 EUR.
So let's say we come to about 6000 EUR rounded up.