Property purchase & broker behavior: Is this normal?

However, we primarily became aware of the property through the listing by the general contractor (Heinz von Heiden).
They then sent us an offer for the house.
And additionally provided us with the address. Their price calculations always include the cost of the land.

Ah, of all people, the favorite Heinz of - well, the plot is large enough to build a chicken coop as well ;-)
In principle, they can certainly have satisfied customers, but I at least recommend obtaining comparison offers from other providers (although, as is well known, I prefer owner-managed regional providers regardless of the construction method).

We will certainly do that. Although with this property, the question arises anyway whether we would have any choice at all.

Not least, I now suspect a tied selling.

We found one or two plots via Immoscout (with builder tie-in)

That was already obvious here.

When asked, the answer was "I have nothing to do with the plot, the agent handles that"

Yes, the "settlement," i.e. the purchase, marketing. Nevertheless tied.

That was already obvious here.

Yes, the "billing", meaning the purchase, marketing. Still linked.

The property tender says nothing about it. Therefore, I am now only interested in whether it is also included in the purchase contract. If yes: then the price definitely has to go down. If no, I wonder to what extent I am bound if it is not even stated in the purchase contract.

If not, I wonder to what extent I am bound when it is not even stated in the purchase contract.

Then you probably wouldn't be, and I would also take advantage of this freedom. Less because it is Gabriele's favorite Heinz, but because the tax office might get hold of such an offer with the included land from another customer of the same company – and then it could catch you off guard by assuming it to be a tied transaction.

so...we were there and we still like it. According to the real estate agent, we are not bound to Heinz von Heiden and nothing about this will be stated in the purchase contract. The "consultant" we deal with regarding the house is simply someone they know and therefore occasionally offer to their customers. However, we would of course not be bound and could also build with someone else. That is of course great, but still, all of this surprises me a lot.... The guy from Heinz von Heiden/consultant said we would be bound to him?!? What also surprises me is that the real estate agent has so far neither received a land register excerpt nor any information about an existing soil report. If they allegedly already had interested parties who were at the bank – did they really not want to know how it looks in the land register?!? We will definitely get other offers regarding the house. Since we are not bound anyway now.