When I started my apartment hunting in Beijing last year, my agent at a top Chinese real estate brokerage with a transaction value of 700 billion yuan ($108 billion) in 2015, soon equipped me with an effective weapon - a friend of his, who pretended to be another potential buyer.

The agent told me if I like the apartment, he could ask his "potential buyer" friend to offer the owner a low price, which would certainly make the owner lose his confidence about the market.

"Then you can offer a slightly higher price. It can help you get a better deal," he said.