The answer to 'how much does backflow preventer cost' is that the cost can vary widely depending on several factors. Typically, the cost for a basic backflow preventer installation can range from $300 to $1,000 or more. The specific price will depend on the type of backflow preventer, the complexity of the installation, the materials needed, and the labor costs in your local area.
Factors that can influence the cost include the size and complexity of the backflow preventer, the accessibility of the installation location, and whether any additional plumbing work is required. More advanced backflow preventers, such as those used in commercial or industrial settings, can cost significantly more. It's important to get quotes from local plumbers to determine the exact cost for your specific situation.