If a broker sets a “standard” broker fee and is unwilling to negotiate lower, what can I do?

To be honest, there’s not much you can do if the agent is not flexible.  There could be a number of legitimate reasons for this, such as the fee being split with another agent, the agent’s firm requirement of a minimum fee or that a more-than-usual amount of work will be required for the deal to get completed.  You can try negotiating, as broker fees are negotiable by law.  However, both sides must agree on the final fee or a deal cannot be done.

Regardless, good advice suggests that you discuss and agree upon the broker fee during the initial conversation with an agent before any work is done, so that you are both on the same page and are satisfied with the terms.  If you do this upfront, then if you’re not happy with the minimum fee the agent requires, you can just move on quickly to a new agent.