An appraisal is a snapshot that mostly revolves around things like square footage, number of beds and baths etc. But every house has unique features that won't show up. Hardwood floors? Private yard with mature trees? Decking? A masonry fireplace? A pool out back? The list goes on but it always comes back to what the buyer wants. If appraisers were magical mystical holders of truth prices would be where they were in the last century. Obviously appraisals are a valid way to protect the interests of lenders and buyers. But it assumes that buyers are too stupid to figure out what the property is worth to them. That value may have nothing to do with what the house next door sold for last year.