I don't have that data. That would be a good question to ask CSIC, whether they collect some of that data.
Anecdotally, I have heard both situations where claimants will say “I was charged the same or even more to go a consultant”, and situations where people will say “The reason I went to a consultant was because I didn't get legal aid and I couldn't afford a lawyer, and this guy was offering to represent me more cheaply.”