You can certainly "fire" an agent that isn't doing a good job of representing you. Just make sure you do it in writing. Talk to his broker because afterall, he is an agent for the broker, and perhaps the broker can help you where the agent couldn't.... more
Daniel, this is an area where I specialize, and I would be happy to help you with this research. A Realtor can give you the data on sold properties. Some web sites try to guess, but it is often inaccurate. Please let me know if I can help you with this research.