The answer to 'price to replace backflow preventer' is that the cost can vary significantly depending on several factors. Typical ranges for a professional backflow preventer replacement can be anywhere from $200 to $800 or more, depending on the complexity of the job and your local market rates.
Some key factors that influence the price include the type and size of the backflow preventer, the difficulty of the installation, the need for any additional plumbing work, and your location. Backflow preventers in hard-to-access areas or that require extensive pipe work will be on the higher end of the price range. Getting multiple quotes from licensed plumbers in your local area is essential to get an accurate estimate for your specific situation.