Does a cross foundation necessitate a pile foundation?

As I just found out by chance from the seller of our reserved plot, a cross foundation is apparently necessary. On the internet, I have only ever found something about this in connection with pile foundations. This somewhat puts me off now, as it means extra costs (calculated with a buffer, but it was hoped not to have to use it). Can you tell me whether a pile foundation is then necessary or not and what extra costs may arise for me?

Thanks
Andre

Where are you building? Sumpf or Elbe?
Who is the seller?

We are far away from a swamp (as far as I know) and the Elbe. The property is in Lauenbrück. There was already an interested party for our (reserved) plot who wanted to combine two properties and had a soil survey conducted. This apparently stated that a cross foundation would be necessary. However, he does not know any details. I will probably have an expert report done in the next few weeks. Does anyone know how much something like this roughly costs?

Approx. €1,500

So, since an expert report has already been prepared by another interested party beforehand, I now know what kind of foundation is recommended. It is a cross-beam foundation. Can you tell me more about this type of foundation?

Google probably knows a lot about that :) As far as I know, it is a pile foundation - not exactly cheap. 20000? Or just call a civil engineer, they will probably know an amount better