Power of attorney for the preparation of a purchase contract

That probably won't work out, because the seller precisely wants to keep all rights to themselves and put all risks on the buyer in case the signature doesn't materialize.

How do you know that? Maybe he (the seller) just told his agent "go ahead"? Agents focus on their commission; this part is also detailed and clearly formulated.

So, it doesn't hurt to ask

Rhenish greetings

Without the appointment scheduling and the confirmation of the broker's entitlement to compensation, the agreement would be without content. So if the self-evident things are omitted, only the risk shift of a failed notary appointment onto the buyer remains. Why bother with the deed then, if it only contained trivial matters?

But asking doesn't cost anything of course

So if the obvious things are ignored, only the risk shift of a failed notary appointment onto the buyer remains.

A draft notary contract is, as the name implies, a "draft". Which simply means that the personal data are entered and the further content is negotiated. Above all, the notary "watches over" this, who is obliged to neutrality towards both parties.

If the seller is not a plaything (gambler) and wants to sell his property, it will be in his interest – provided the financial matters are clarified and proof of capital is present with the buyer – to get the notary contract over the line as quickly as possible. This also means, conversely, that he can have, for example, the 2nd paragraph I proposed, formulated this way or something similar, included in the contract without necessity. Because he is only liable for the notary costs if he himself causes the signature appointment to fail.

If I had accepted our first draft so fatalistically, we would all be stuck with the possible development costs. So, as the late Helmut always said, a little something always works

Rhenish greetings

The client(s)
(and)
(hereinafter referred to as buyer)
hereby commissions and authorizes:
xxxxxxxx
to have a notarized purchase agreement prepared by a notary. .

In my opinion, this passage is now the basis for a possible claim.
After reviewing some case law and the Court and Notary Costs Act, I revise my opinion from #8 (owner must) pay.

§ 29 Court and Notary Costs Act General debtor of costs
Notary fees are owed by the person who
1. gave the order or made the application,
2. assumed the liability for costs toward the notary, or
3. is legally liable for the cost liability of another.

There is an annex (to § 3 paragraph 2) to the Court and Notary Costs Act that contains the fee schedule (KV). For the drafts, Preliminary Remark 2.1.3 applies:

Early termination of the notarization procedure
Preliminary Remark 2.1.3:
(1) A notarization procedure is deemed to have ended early if, before the signing of the record by the notary, the notarization order is withdrawn or rejected, or if the notary determines that, in his opinion, the commissioned notarization is no longer to be expected for reasons not attributable to himself. If the procedure has not been pursued for more than 6 months, notarization is generally no longer to be expected.
(2) If the notary subsequently carries out a renewed notarization procedure on the basis of the already performed notarial activities after the early termination, the fee charged under this section will be credited against the fee for the renewed notarization procedure.
(3) The preparation of a draft within the meaning of the following provisions is equated with the review, amendment, or supplementation of a draft submitted to the notary..

In short
The drafts are chargeable, albeit somewhat cheaper.
The client must pay – according to the Federal Court of Justice at least if he expressly orders a draft. The crucial question is who the client (for the notary) is. The basis is the power of attorney, which enables the order to be placed via the (hidden) mandate to the broker.

It is well described here (->Google):
Notarization failed – notary costs for draft purchase agreement?

The good news: Both the interested party and the owner are jointly and severally liable according to the specific article.
BUT: Because of the hidden "placing of the order," one might possibly see it differently here, that only the interested party should pay (although obviously not willingly).

§ 32 Court and Notary Costs Act Multiple debtors of costs
(1) Several debtors of costs are liable as joint debtors.
(2) Additional costs arising from special requests of a party shall be borne solely by that party.

Thank you, Otus. As you explained in detail, that was the intention of my short contribution.

Indeed, it is quite "hidden".