The costs of online courses vary between $0 and thousands of dollars. No matter who the creator of the course is they can charge as much for it as they wish. If they feel that a one-hour course is worth $5000, they can charge that much. It is up to the customer to decide if they are willing to pay that much.
Usually, I write about online learning possibilities on this blog. This time, though, I wanted to tell you this story to remind you that no matter how much you try to plan and study beforehand, the reality is complicated, and you cannot prepare for everything. Sooner or later, you just have to take a chance and try things.