The answer to 'how much to fix air handler' is that the cost can vary significantly depending on several factors. The price to repair an air handler can range anywhere from a few hundred dollars to over a thousand, depending on the specific issue and the complexity of the repair.
Some key factors that influence the cost include the age and condition of the air handler, the type of repair needed (e.g. replacing a blower motor vs. a complete system overhaul), the brand and model of the equipment, and your local labor rates. It's best to get quotes from multiple HVAC contractors in your area to get an accurate estimate for your specific situation.