I think the best way to determine if you have a good teacher or school is to listen to the sifu or sensei or master... whatever.
if they try to feed you the old "you will be able to fly like crouching tiger hidden dragon"... it's bull. I was skeptical about a little kung fu school with only a handfull of students of any level, but I did my research and found my sifu to have a similar mindset as myself. military background (an impressive one at that), lineage, and a no bull attitude. I'd bet that most people who get ripped off simply don't do their research. It's not hard and you might find yourself face to face with a world renowned master