Not a bad idea...
...But I suspect the type of people who benefit most from GC are those who benefit most from the read-lots-of-books-and-practice approach. Don't get me wrong, there is more useful info in the GC archives than there is likely to be on this or any other course, however, it is going to be hard to digest it if you are the type of person who likes to obtain information in the traditional formatted chronological manner with reference to expert opinion on the fine details.
If you are the kind of stream-of-consciousness random access learner I am, then save yourself $787 and get GC.
Otherwise you would be spending $800 to have them review rather elementary material for you.
One reason I didn't dismiss this out of hand was that they appeared to be teaching the advanced stuff as well as the meat and potatoes of card counting. You won't learn about sequencing for example from GC, the information just isn't there. Of course, its quite possible they may be teaching it badly, in which case the course has negative value.