The answer to 'cost of maintenance' is that the cost of HVAC maintenance can vary widely depending on several factors. Generally, regular maintenance and tune-ups for a typical residential HVAC system can range from $75 to $300 per visit, but the exact cost will depend on the size of your home, the complexity of your system, and your local market rates.
Factors that can influence the cost of HVAC maintenance include the age and condition of your equipment, the accessibility of the system, the need for any repairs or replacements, and the experience and qualifications of the technician. It's important to get quotes from multiple local HVAC companies to find the best value for your home.