Monthly subscriptions were offered in the first few months to existing PRO EDU customers at a discounted price. We have ended monthly access and now offer annual plans that unlock unlimited streaming to the entire platform.
Please note that pricing is always subject to change. If you signup for a monthly or yearly subscription, you are "grandfathered" in and you can always remain on that plan if you should so choose. But if you cancel, then any existing plan that is no longer offered will not be available again.