Obviously, it's an extremely bad idea to price your name based on what GoDaddy's said.
However, I do not think that GoDaddy's estimation is totally useless and a complete garbage, as some people suggested.
Let's be honest - if you run 1000 potential names through GD appraisal, and then their system says that 50 of them are valued more than $2500 and 15 are valued more than $4000, would you like to see these specific names? Raise your hands those who say - ''no, I wouldn't spend even a 20 sec of my time looking at such names''.
And it doesn't matter what you later think about these domains and how you price them (if at all!) - you will check them out first.
So, to me GD appraisal does have a value in the sense I described.
But of course, if you are a newbie - do not price your names based on the digit GD brings for it. Never.