Plot of land including turnkey house - experiences?

But you seem to be resistant to advice anyway, so do as you please. It's not my money.

I'm just gathering information here, nothing more, nothing less. I also have no intention of signing anything before I am 100% sure what I am getting for my money. I am far from committing to the deal because I simply lack more detailed contracts, performance descriptions, etc.

Do you even read what people write here?

Yes, I do!

House connections/drainage is very little, but you can find out yourself from the city/the utility providers what that costs in your area. Earthworks 6k is also an absolutely flat plot. Not much can be done for that.

How are the outdoor facilities designed? How much is to be paved? Terrace? Entrance platform?

Everything very tightly calculated.

At the moment, there is a demolition object on the property. The property looks relatively flat as far as I can judge as a layman. For the outdoor facilities, I have calculated about 18k myself with terrace, hedges, fence, etc.

The plot looks relatively flat, as far as I can judge as a non-expert.

If it only looks relatively flat, it’s not ;-) if you have no experience in assessing terrain surfaces, you can easily be mistaken. As an example: our plot looked virtually flat to my husband as well... I thought it had a slope of at least 1.5-2m over the 34m (I am an archaeologist and therefore have more eye for it). I was ultimately right... it’s about 2m. That’s of course not much but depending on the desired house, it’s enough to require filling/cutting/somehow leveling.

What is meant by "demolition costs (proportional)" in the offer? Is €10,000 enough?

What is meant by "demolition costs (pro rata)" in the offer? Are 10,000€ enough?

Yes, those are fixed because the existing building extends over 4 new plots which are then distributed among the buyers.

But I find the costs of 172k for 399m² of land + 10k for demolition simply totally excessive. With that they basically knock themselves out right away.

If it "only" looks relatively flat, it isn't ;-) if you have no experience estimating terrain surfaces, you can easily be mistaken.
As an example: our plot also looked almost flat to my husband... I thought there was at least 1.5-2m slope over the 34m (I am an archaeologist and have accordingly more eye for it). I was ultimately right... it’s about 2m. That’s of course not much but depending on the house wish it’s still enough that you have to fill/cut/somehow level it out

Ok, thank you very much for the hint.

My tip: First, also calculate the expected property tax, many forget or simply overlook it. Otherwise, you have to factor in the realtor's commission and better always calculate a little more.

My tip: Calculate the expected property tax in advance as well, many forget or simply overlook it. Otherwise, you have to factor in the broker's commission and it's better to always calculate a bit more.

You probably mean the real estate transfer tax...….