You can check out all the group exercise certifications in the industry here https://www.ideafit.com/certifications/group-fitness
Once you are there you can filter the results by cost.
There are some great posts and articles out there pertaining to the quality of certs, and most of you will be surprised to find that no client will ask you if you have a certs; and most gyms will spell out what they want. Does it ever occur that the training and education you receive will result in the form of experience, hands on and keeping your knowledge base engaged. Some of you may consider going into business for yourselves. Now as far as new trainers and private trainers starting their own programs, maybe a cheaper cert such as Fitour may be the right choice.