This is a very strange situation.

Whom is your lawyer in this affair?
Whom is your agent representing you?
I have not heard ever of a client expected to pay the capital gains tax of the seller. Of course every contract is to negiotiated.

The point leads to in what ever country you buy or sell in, get proper legal and professional services. Agents make money by providing a service. True not all agents are not correct.

But you should have a lawyer and agent, and thank good ness the notary explained the situation.

Very irregular. Who do you get yourself involved with. Get professional help. You will pay for this, but it is money well spent.

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