House construction in the Stuttgart metropolitan area?

Hello Fories,
At the moment, we are still somewhat in the dark about the costs of building a house in our area :confused:
What minimum costs should one expect to put up a single-family house?
It is purely about the house; the plot is already available.
We have an offer for 200,000 euros, but somehow it seems low to us, so we would be very grateful for any experiences. Can you really get by with that? We are envisioning a house with about 120 sqm, possibly without a basement.
Regards
Dennis

Hello you Swabians, where are you all... at the station ;) ? We would be so happy about some experience and unfortunately no one in our acquaintance has built new...