IMO, you can learn Russian on your own but you will loose alot of time. Because in Russian grammar, there are lots of concepts that will take lots of time for you to decipher on your own. But a teacher will tell about them instantly and you will learn much more fast. So, it is better to study with a native Russian teacher. Even 1-2 hours a week would be enough than the rest of the time you can study alone. I think it worths the money. Goodluck.