Is $300 to clean the blower a fair price?

The technician performed a yearly inspection. I am concerned about the flue pipe potentially leaking gasses, especially since the technician initially downplayed it by mentioning carbon monoxide detectors. I am also skeptical about the necessity of the blower cleaning as it doesn't look dusty to me. I've used this company for years, but I'm now considering getting a second opinion due to these concerns. I am handicapped and unable to inspect the flue myself.