The main advantage of the live vs. self-paced class is that it forces you to keep a schedule and moves you along. You also get access to a teacher and get a better sense of how things are moving but in a grand scheme of things, a live class is often not all that substantially different from the self-paced one. Just want to make sure your expectations are set correctly.
At the same time, from our research (now years ago), we have noted that self-paced folks improved 110 points approx. across many courses while live-class students were closer to 140-150 points, so there is clearly a difference...
What are you looking for in a live class?
If you are looking for one, I would consider attending a
MGMAT class - I believe they used to let you attend at least one for free.