Actually Wayne, we have laws that say we cannot regulate fees. We have anti-trust laws in the US that make price fixing illegal to protect the public from such practices. I would also say it is a very touchy subject, I would not want to be near two brokers who are discussing what they charge as such a discussion among even 2 brokers could be considered "price fixing".
In answer to your question: I believe we all charge what we think we are worth!
When I give a presentation to a seller, I don't think about "justifying my price". Rather, I am so confident I am worth that commission that it is easy to ask for, and I expect they'll feel I'm worth every penny.
Hope that helps!
Raving Real Estate