Agreed. "The university of Youtube" as I call it, is where I learned most of my cake decorating skills. I graduated from a baking and pastry program which, as mentioned above, only gave me the basics. I could travel down Negative Nancy Lane on the whole school subject, but I will say this: yes, I made good connections, and yes some of my classes were worth the money, but only a few. I went to school to be a pastry chef so our goals may be a bit different, but if cake decorating is what you want to do, learn from the people here, on youtube, or with online classes, etc. Many of the people here are very willing to share their techniques and experiences. It really is what you make of it, if you are driven you will succeed!
All in all though, not worth the money to only learn how to decorate cake.
Instead of spending so much money, maybe you could fly out for a specialty class with one of your favorite cake decorators?