When I run my CMAs, I put the MOST weight on active and pending listings. I try to price the listings based on how the competition is priced and how long they have been on market. In the end its all about the principle of substitution.
Even with years of experience as an appraiser, I’m not good enough to come up with a single point of value as a sales price (mortgage work is a different topic). Buyers are emotional and don’t always make logical decisions. As a broker, I believe single point values leave too much room for leaving money on the table.
Like you said, its all about educating and manageing the seller’s expectations. I won’t accept listings that are unreasonably priced and I won’t promise the moon if I can’t deliver. I think an appraisal class should be mandatory for all R/E agents.