I decided to buy a home for my personal residence once. It was very good idea in the beginning to find the properties are offered by owner, therefore I could save both sides commission I thought.
After I was searching for over 6 months and look over all properties for sale, I realized for sale by owners are offered higher price then fair market value!!
Since I am realtor I found out that most of the times "not always" Home owners offering their property for sale over priced. That could be because of they don't have access to the MLS or they are not able to get accurate CMA, or that could be because they are emotionally involved and they are not willing to let the home go with the price is the real value.
So, I ended up going and looking for properties that are listed with an agent and they have been on the market for longer time. Why longer time?! Because I learned, many agents are trying to get the listing and not able to list with the fair market value. What is happening at that time: The home will be in the market for quiet while, and after listing gets expired, now the owner is sure that if he/she is planning to really sale the home they have to drop the price. Which some times they rather to try another agent whit lower asking price, I call them "lucky agents" who is the one receives ready transaction with motivated seller!
Of course this is my personal experience and I know there are many exceptions and alternatives.
FSBO do have a tendancy of asking higher than market value for their homes in our market as well. The most common comment that I hear when I ask "How did you get that number?" is well I know that such and such up the road sold for blah, blah and ours is worth more than that. They often do not understand that there is a lot to consider in such a comparison.
We do see some that list too low raising eyebrows and questions like--what is wrong with it. I see that those are often when the homeowner just looks at their taxable value and asks for less than that. Not good in our local market.
As far as those agents go that are unsure how to comp out listings--that will unfortunately be never ending...