You need to define “expensive”. A BMW is expensive, but only because you can compare it to other cars. A $200,000 house is cheap compared to a $1,000,000 house, but it’s expensive compared to a BMW. However, since it would make no sense to compare a house to a BMW, we would probably agree that the $200,000 house is cheap, assuming most other houses cost more than $200,000.
Similarly, for you to describe the CFA process as expensive, you need to define what you are comparing it to. I would argue that it is cheap relative to other certifications with similar benefits to your resume.