No matter which dynasty or era, buying a house and land is always a big deal. It's not like you just take out the money and I simply agree; it's not as if the deal is finished.
That's just play acting.
In the Dayong Dynasty, if you want to buy a house and land, you have to first draft a contract between the buyer and seller, then go to pay the contract tax, and only after obtaining official approval is the transaction considered complete.
Xu Qing drafted a preliminary contract with the broker's steward, which was the purchase agreement for the house. Then they went together to the government office to register with the clerk in charge of population records.
After completing this, he also had to pay out of his own pocket to buy several "official contracts."
The official contract comes in four copies, each of which must be exchanged with real gold and silver.