The bottom line is if you believe your agent is totally wrong about what he or she thinks your house should sell for or if you are selling without a broker altogether, then get an appraisal.
Otherwise, hold onto your checkbook. It is possible, when well negotiated, to have the appraisal paid by the buyers. In addition, our office offers a complimentary CMA (Comparable Market Analysis) to assist our clients when deciding how much they should sell their home for in the current market.