I see several sites that will appraise domains, but do they calculate real value or perceived value? Or does it even work?
simple answer no. its not a science, its what the buyer is willing to pay. a better judge of value is the website as a whole.
The honest answer here is no. Do not waste your time and money using appraisal services as they are almost always inaccurate. To be honest, the most accurate domain appraisal website I have found is actually free (to do one appraisal per day) and that's at estibot.com A domain is really only worth what someone is willing to pay for it. Don't bother paying someone for an appraisal or asking what one or two websites tell you to ask online. Use NameBio.com to see what some other relevant domains have sold for in the past and come up with a fair price in your mind. Then, try to target that instead of what some appraisal tells you.
If you do it yourself, you can come up with an appraisal that will have some value. The age of the domain, number of owners and a variety of other factors should be factored into this appraisal. The domain appraisals sites don't give any real indication of the value of the domain, so it's better not to use these.
Automatic domain appraisal systems are most valuable for filtering through a big list of domains, to find some potential gems. In the end, the value of a domain is a function of what an end user is actually willing to pay for it. If you're looking through a list of 100 names to buy, a good appraisal tool would quickly help you identify the keywords in the domains, the search volume and CPC for those words, and a rough estimate of the value of a domain with that many words, characters, and TLD