Real estate transfer tax - community of heirs

If the house was appraised as part of the inheritance, you can also write 1€ in the purchase contract.
However, the tax office will always use 50% of the appraised value as the taxable amount. They don't put on their pants with pliers either!

And on the difference amount, gift tax will probably be applied...
That could then backfire badly.

Thanks for the answer. Then I should probably look for a good tax advisor who knows about this ;)

Roughly estimated, the brother's share is lost for tax purposes (meaning GrErwbSt is the cheapest option).

For the grandmother's share, you can still optimize a bit... Meaning if significant assets are present, distribute them to the future heirs now.

Significant assets would be anything exceeding the exemption amount... So rather beyond 1 million, depending on the number of inheriting persons. Just calculate using the inheritance tax table.

But since this is not my price range, better to talk to a tax advisor/notary. And read up on this topic yourself beforehand. Well intended is not always well done.