Estibot is for entertainment purposes only
I don't think that many veteran domainers here would put much stock in an appraisal using estibot. The valuations on some names are simply absurd. I have many names that I will gladly sell for 1/3 of the Estibot appraisal, even though I think they are good names.
I haven't found any reliable appraisals for domains that will carry weight with a buyer unless the buyer is a newbie.
NameBio to me is the best tool for estimating worth of domains based on similar domains.