I would like to hear some ideas and the things that should be kept in mind while buying a domain name from another user on domain forums and other domain marketplaces. Not for domain registrations this is for buying the existing domain names.

What points should be kept in mind?
What kind of things are there that matters while buying an existing domain name?
Should we get a certified domain appraisal or not?

There can be other opinions also. But I don't know what kind of things are there that needs to be kept in mind while buying a domain name. I have always brought the domain name if I liked the domain name itself.

First of all it will be pronounceable and second show the domain length and third is what you have idea to develop the domain.