Being a buyer is it Legal to pay commission to your agent?

[Telwin Edathil]

For example, lets assume the property you are interested in buying is listed at 500k. 

Then can you commission your real estate agent based on how low he/she can bring the price down with negotiations.

(Since I feel getting the price down actually reduces the agent's commission can we offer a commission from our end to ensure a great negotiation.) Is it legal or illegal?