What do you think something like this costs including heating?
This can only be quantified once the preliminary assessment has been carried out. Then the actual demand (capacity, energy) for heating and domestic hot water is known. This leads to the appropriate heat pump, the extraction capacity and energy for the source, and thus to its required design (size) and finally to the material costs for this.
In any case, significantly cheaper than a vertical borehole by a drilling company. The rest as usual => specification of the type of heating surfaces, heating surface calculation, pipe hydraulics, etc..
Best regards.