Property purchase - Risk of a "linked transaction"?

What is meant by „Leerverkauf“ here? The plot and the owner do exist as stated, both have been seen in real life.

Therefore, I also think that this is probably not a short sale here – but I do not want to completely rule it out: if the approval cannot be obtained so soon, it could still only be intended as a vehicle for construction contracts. By the "short sale" in my posts on this topic, parcels of land are usually meant that the seller cannot actually offer at all: house salespeople take size and location details from real land listings, add to the land price the purchase price of a theoretically buildable house model from their catalog based on the plot ratio, and post a land listing as if they were selling that house on that plot. In truth, however, they do not even have the consent of the owner of the real plot and want to scam a construction contract with the offer. The victim's interest is often even forwarded to the seller, with whom no deal is made (often quite simply because the plot has long since been sold). The victim is then offered substitute plots that are often unacceptable, and then buys their way out of the construction contract.

As I said, I have met the seller personally and would not want to accuse him of criminal intent or “half-baked” ideas – it already sounded as if he had extensively informed himself on the subject.

To me, it sounded rather as if he was only just informed enough to know the quantity limit for sellers who want to be considered private. Our school wisdom cannot even dream how many people believe that overly clever tips from tax advisors may be dubious but always legal, because they supposedly know best and cheat in a formally correct way. They should better pay attention to what the advisor tells them exclusively orally, makes them sign themselves, and preferably wants to be paid in cash and without witnesses (we will discuss this on Sunday at the morning pint, just for your ears, feel free to leave your wife at home, wink wink).

Relax ;) I'm really not as naive as it apparently comes across here! What is meant by “short sale” here? The plot of land and the owner do exist, as I said, I've seen both in real life.

I don't think you're naive. Someone naive probably wouldn't ask. This is the biggest investment in life. I asked my husband how the procedure with the plots of land was back then. We didn't have to take care of anything, the notary contract for the shares of the plot was already delivered to us completed, all landowners were present at the appointment and met each other there for the first time. We suspect that the realtor arranged everything, he found this plot. He has also managed larger construction projects before and took care of the marketing. We didn't have to worry about GBR or anything like that. At that time, there was not a single building plot available for us, initially it was about becoming landowners with the option of a row house. As I said, we could also have built with Schwörerhaus or local construction companies, we were completely free, but we liked the concept of the GÜ. At that time, we had only received proposals on how the house could look. The house purchase contracts were only made much later, financing was clarified first, then the planning started, and only then was the house price fixed.

I have just discovered a document from the Federal Ministry of Finance that appears to be a kind of guide for the assessment of real estate transfer tax and lists quite a few different scenarios and how they are to be evaluated in terms of real estate transfer tax. Just google „grunderwerbsteuer bundesfinanzministerium 2017“ (PDF document) for this, in case this document is not already known here in the forum...

So, we had another conversation with the sales consultant. I hope it’s okay that I continue the thread here regarding this matter; the contract topic was already discussed at the beginning...

On the one hand, we are supposed to sign a planning contract (basic evaluation, preliminary planning, design planning). This is supposed to cost €4000, which will be credited back when signing a house construction contract. Fine by me, as we want significant changes from the standard design.

BUT, we are also supposed to sign the house construction contract right away? This is based on the construction and service description of the standard house, supplemented by additional features we would like to include. However, regarding the floor plan, window areas, etc., it is still far from what we envision (actually what the planning contract is for?).
There is a right of withdrawal if financing is “demonstrably not possible.” According to the sales consultant, this automatically applies if we decide against purchasing this specific plot of land (since financing is not possible without land).
Still, the whole thing somehow leaves a “bad taste” for us – is this approach usual with reputable home builders? Shouldn’t the planning contract be sufficient at first until the planning matches our ideas and the total price is determined?
I would really appreciate your opinions.

I consider the 4000 for the planning to be okay, provided that the plans are also received. Signing the contract at the same time seems unprofessional to me.

I would definitely not date a house construction contract before the notary appointment. If the date is before the notary appointment, you are no longer free in your decision at the time of the land purchase. Furthermore, I would have one or two alternative providers prepare additional offers for building a house on the land.

The sequence has to appear plausible
Notary appointment ---> offers ----> construction contract

With this approach, I was able to answer the questions on the questionnaire in good conscience, even though we had already planned very far with a construction company before the notary appointment.

Another question on the questionnaire was how you became aware of the land.
However, the questionnaires vary from state to state.