I teach NetWorker Admin I and Advanced courses and even folks who have been working on Legato for over a year seem to get a lot out of my courses. The 6.x courses are a lot better than the 5.x classes were. I'm getting very positive feedback about the 6.x courses and how they have helped my students.
The Advanced course is for very specific areas, NDMP, Lib Sharing, Remote Storage Nodes, Clusters, and Performance Tuning (allow this is the weakest chapter). Unless you are needing help with these areas you should go to Admin I. The 6.x Admin I course now includes what used to be in 5.x Advanced and Installation courses.
There are companies that charge less than $3000 for the course, like Lexicon inTexas and IMS Systems in Maryland.
I recommend you attend training. It can be very insightful.