Dear beetcoin. Well the purchase can be done by 2 ways, Remotely, you are sending a notarized letter of attorney on the name of whom you trust so he can make the deal in notarized office in here OR you come here by person. Once you or your authorized person  are here, we go to notarized office and making a preselling order which describe the protocol of buying and selling deal, which describe the following: During 3 hours your side as buyer is taking a notarized responsibility transfer 200 bitcoins on my bitcoin wallet address which I am providing, and my side as seller taking responsibility to transfer the rights of ownership to buyer,  once the money is deposited on my account, again it is being confirmed by notarized office and you get full rights of the ownership of apartment, if you not deposit the money during 3 hours the agreement will be abrogated. Everything will be happening in the presence of a notary, so both sides will be protected by law, everything will be documented.