Study site, Study.com or Petersons

[btinnc]

I am looking to take five DSST exams over the next 3-4 months. I have subscribed to InstantCert in order to use the flashcards, but would like to also have a single source I can go through study material without needing to hunt and search for the best study site for each subject. 
I see that Study.com and Petersons both offer study videos, and they are both between $50-$60/month. For anyone who has used both, which do you prefer and why?

For those interested, these are the five exams I will be taking, in the order listed. 

DSST Exam: Introduction to World Religions
DSST Exam: Business Ethics and Society
DSST Exam: Organizational Behavior
DSST Exam: Astronomy
DSST Exam: Foundations of Education

Thank you