Hidden fees in Karate

I took karate as a kid in the 90s. There were no contracts but I don't think my parents were told there were exam fees for belts/steps. For yellow belt 1 and 2, the testing fee was about $70 in todays dollars. For green belt 1 and 2, the testing fee was about $85 in todays dollars. That is where I stopped. For the next belt up, my guess is the testing fee would be about $105 in todays dollars. Oddly, I knew the black belt testing fee, which was about $725 in todays dollars

Testing was every 3 months and can not recall someone not passing.

Is not telling someone interesting in joining about testing fees considered unethical?

Is it considered unethical not telling a potential customer the testing fees go up for each belt unethical?