The answer to 'how much to fix backflow preventer in my area' is that the cost can vary significantly depending on several factors. Typically, the cost to repair or replace a backflow preventer can range from a few hundred dollars to over a thousand, depending on the complexity of the job and your local market.
Some key factors that affect the price include the type of backflow preventer, the accessibility of the unit, whether any additional plumbing work is required, and the labor rates in your local area. Backflow preventers located in hard-to-reach areas or that require extensive excavation will generally cost more to service. Additionally, the age and condition of the existing unit can impact the overall repair cost.