To purchase a real estate asset legally with crypto, you will have to go countries where crypto is accepted legally, because without that, it will be a bit difficult doing that except you happens to meet a real estate agent willing to transact with you in crypto one on one.
There's no other option if the property you want to buy is only accepted in cash or even if the owner wants to receive the payment in crypto but there has to be some taxation and paper works that will matter due to this sale.
That's why they have to go through it like having an actual transaction, p2p and then they'll also talk about the tax and other paper works. It's all a matter of talks and agreement.
If not, then just go with the traditional way of selling it for cash and hand over the money to the seller but it will take time.