The answer to 'how much to replace air filter in my area' is that the cost can vary quite a bit depending on several factors. In general, you can expect to pay anywhere from $10 to $50 to replace a standard HVAC air filter, with the average being around $20-$30. The exact price will depend on the size and type of filter needed for your specific system, as well as whether you DIY or have a professional do it.
Some key factors that influence the cost include the size and quality of the filter, whether it's a basic pleated filter or a more advanced HEPA or electrostatic filter, and whether you need to purchase the filter from a specialty HVAC supplier or can find it at a local home improvement store. The labor cost to have a technician replace the filter can also add $20-$50 or more depending on your location and the company you use.