House purchase - Price OK? Experiences?

What is often forgotten is the nervous component. One must always ask oneself if one wants it and if one feels capable of it.

One should seriously consider building

I would also say that the new building is likely to be more expensive, and if you like the property, you should definitely go for it. Especially with new houses, there is often not much room for negotiation because eventually someone will pay the asking price, as long as it is not completely exaggerated. Regarding energy demand, even a KfW70 house from 2009 of that size should be heated for about €1000 per year. Now you can calculate how long it takes for, for example, an additional expense of €30,000 to pay off if you only use half as much energy.

So for me, that sounds like a good price, provided your information about the quality of the object is correct.