Looking for a place to live in Hanoi, how does it work with an agent?

The housing market in Hanoi is a bit different from some other countries. One house can be advertised by some different agents or agencies and sometimes it is at different prices on a same property. Expats can choose to work with many different agents and agencies at the same times, but you should choose a good agent to work with, because all the agents may have the same database and will show you...