Some of the appraisals were accurate on my private domains. But they offered alot for an undeveloped domain. Best appraisals come from here.
SwiftAppraisal is very inaccurate along will all other free appraisal services. The ones that rely on user inputted information like SwiftAppraisal are especially inaccurate. Definitely do not rely on this appraisal site for accurate market value appraisals. If you have a domain that is worth it then get a certified domain appraisal that will serve as an actual basis for selling instead of a free, inaccurate appraisal.
No, that software is incorrect and always over exaggerates. A domain that I use to have and sold for $50 was estimated at $80,000. Experts told me my domain would never be worth more than $100.