The answer to 'how much to replace duct cleaning' is that the cost can vary widely depending on several factors. In general, professional duct cleaning services typically range from $300 to $700 for an average-sized home. The exact price will depend on the size of your home, the number of vents and ducts, the level of debris and buildup, and your location.
Factors that can influence the cost include the accessibility of the ductwork, the need for any repairs or replacements, and whether you require additional services like sanitizing or sealing the ducts. It's best to get quotes from multiple local HVAC contractors to compare prices and services.