I thought I replied yesterday, but my words may be lost in cyberspace. To briefly recap:
As the marketing guy (pitchcoach for my clients) who has been to more than a few meetings with investors, I'm not big on the pay to pitch model either. As others have mentioned, the organizers make money and the pitchers...not so much.
In ANY meeting, you really have to have all your materials ready - you know Guy Kawasaki's thoughts on the pitch deck, right? - from the idea, to the advantage, to the financials, to the offering. If you're presenting to a big group with dozens of other firms competing for their attention too, you'll need a killer show. Hard to do.
In my experience, I've never seen serious money or backing come out of a big show like that. Targeted networking and one-one-ones and sit-downs with the reps of investors groups have been more effective for raising money and support.