When your realtor writes your contract, be sure to have him include your right to approve who the buyer uses as a mortgage lender. Some lenders are notorious for purposely underestimating property values, and real estate agents are often familiar with who these are. You can't ask for a certain person to do your appraisal, but you can be specific about that person's competency, and your broker can reject someone she knows isn't right for the job. If working with an AMC, be sure to ask for a senior residential appraiser who has experience specifically in your area. And be sure to put it in writing.