Out of curiosity, could you break down some of the costs a bit more and explain what equipment is needed? I've never used AltspaceVR before so I don't know much about it.
Livestreaming hardware / streaming costs
What kind of hardware are you looking into using? Are you going to have to run a server or something to host this little virtual world? What are the streaming costs?
Physical location rental (3 days) for event (fiber optic connectivity needed)
Does this fall into the same question I asked above? Or is it just for fun as a 'studio space'?
Promotion (PR, coincalendars, some advertising (Peakd, Twitter))
Does that mean actual Twitter advertising space? That'd be cool.
Developing HiveFest event world, 3D models
Is there anyone from Hive doing this? It would be cool to see someone hired through Hive to contribute to it.
Do you have plans to reuse all of this stuff again in the future? More virtual events for community purposes?