First, I wanted to thank all of the Effective Altruism Global organizers and participants. I found it to be very valuable and overall well put together. There was obviously a ton of work put into it, most by conference organizers who I don't believe will get that much credit for it, and I very much commend their work.
That said, there's always a lot of room for new ideas, and I find I often get a bunch of ideas at and after these conferences. Because of the EAGx events, ideas described now may be able to be put into action somewhat soon and experimented with.
As may be expected, I recommend that people make all of their ideas be independent comments, then upvote the ideas that they think would be the most useful.
I wasn't there but I'd suspect that people are just talking and socializing during most of that hour, and many of them would be doing so anyway. So the real cost is a lot less than $10k.