Looking to purchase a reliable Mercury 20 HP 4-stroke engine? Figuring out the present price range can help you cash. New Mercury 20 HP 4-strokes usually price between $3,500 and $5,500, based on features and vendor markups. Secondhand Mercury 20 HP 4-strokes often fetch for $2,000 to $4,000, influenced by shape, time and complete state. Note to ex