I don’t really like such questions as they are always opinion-based. In my humble opinion, some of the courses are definitely worth every penny. How much money would you pay for a course in your area? How much money would you pay for a tuition and stuff? You can’t expect to become a coder after finishing one course, but you can gain A LOT of knowledge depending on your attitude.
I have bought a few courses on Udemy, and I’ve been very happy with them.
If you buy a course, and you don’t like it, Udemy is going to give you a refund. (30 day money back guarantee)
Note: The course mentioned above is one of the best I’ve taken.