This blog belongs to Tom Horn, a Birmingham AL appraiser who has lots of good content. He gave me permission to post his blog, so I am copying the link here:
In essence, he gives four reasons to consider getting an appraisal even when you are paying cash for a house.
1) To verify that you are not overpaying
2) To know how your house compares to the rest of the market
3) As a tool for negotiation
4) For lower taxes
I hope you enjoy his article.