Let them go. If the only thing they are looking at, is your fees, they will find someone cheaper next year. 21 years in this business, and I have a long file drawer full of "looking for cheap" folders. "If you are looking for the cheapest, I am not the person to talk to. If you want the best in the area (Mention any credentials) then we can talk.
When a person asks "What do you charge?", I ask them to send me a complete copy of their previous return, then I can give them a more accurate quote. (subject to change, if situations arise).
Also, if people start complaining about my price, next season there will be an increase. I find out, if they come to me for my professionalism, or just a price.