Aren't an agents clients the sellers of the property? What ever gave you the impression buyers are their clients? You bag out agents in other posts, yet you're wanting them to secure bargains for buyers and act against their clients best interests?!
At the end of the day an Vendor is the agents client, however the purchaser will possible be the agents new client especially in an investment property. It has been my experience that any agent worth his salt is aware of this and runs a fine lien between vendor and purchaser., they tend to look for a mutually beneficial outcome between vendor and purchaser, a win win if you like.
On the other hand you have agents that are purely focused on the vendor, and other agents that are purely focused on the buyer.
The difference between getting an extra 5k on top of a price means the agent will at best get an extra $100 in his pocket, compare that to 6 or 7% of rental income he may get from the prospective buyer week in week out.
Even though an agent is supposed to work for the vendor I do not believe that it is as clear cut as all that.