Good deals do happen and on occasion I do appraise properties in excess of their sale prices. Obviously, those appraisals don’t turn out that way without there being a preponderance of data to support it, but it does happen.
How a lender treats that loan application is their decision. Some lenders will base their loan on the sale price regardless of the higher appraised value; others will adjust their loan based on the appraisal. Their money, their rules. Our job is to observe and report, not to participate in the lending decision.
Having said that some appraisals do come in higher I should probably point out the obvious fact that it’s far more common for me to appraise a property for less than it’s sale price. That happens about 30% of the time. Again, a lender will not treat a “low” appraisal as credible unless it clearly shows that preponderance of data. It takes a lot to overcome the natural bias in favor of a sales contract involving a willing seller / willing buyer.