Reliable Sources other than CMA for real estate value in unfamiliar markets.

I'd poll a couple different realtors who service the areas you listed. Make at least five calls so you will have enough information to make a decision. Dual agency is a red flag. Who is the agent loyal to? Any other questions you can contact me at kennon.hughes@ahdcompanies.com Good luck.

I would disagree with Kennon up to a point. Dual agency isn't a red flag. Agents who just want to get paid - regardless of who they represent - is a red flag. I've had dual agency deals before and had repeat buyers and sellers from it with no issues. Without knowing the area myself, I would agree on contacting a few agents in the area to see if they find anything better. Just be sure to tell them what's going on and that they can represent you if another better property is found.

Contact some local brokers. They often are more accurate than CMA's.
http://www.gregorygarver.com

Hire an appraiser or your own broker. Dual agency is a very tricky situation and in my opinion the dual agent always represents the first one in better. In other words if he had the proeprty listed, then he is the seller's agent.