I'm not knowledgeable about summits / conferences. Is $600 a little or a lot? It sounds like a lot to me when I convert it into other ways to spend the money, but maybe this is normal for these things...
$600 is not a lot at all. Most business and non-profit summits easily pass the $2K range, and that's without throwing in deliberate ostentatious signaling.
This is a followup to Ben's post announcing the 2014 EA Summit.
The Effective Altruism Summit is now exactly one month away.