The answer to 'how much to fix system upgrade' is that the cost can vary widely depending on several factors. The overall system upgrade cost is influenced by the age and condition of your existing HVAC equipment, the complexity of the new system, the size of your home, and your local labor and material costs.
Generally, a full HVAC system upgrade can range anywhere from $4,000 to $15,000 or more. More extensive work like replacing ductwork or upgrading to a higher efficiency system will be on the higher end of that range. Getting multiple quotes from local HVAC contractors is essential to understanding the specific costs for your home and situation.