Hi,
I know it may be too early to ask that, but I promise to send another notification related this issue in the coming months :)
We started last year to make the Wikimania costs more transparent. Wikimania is our biggest and the most expensive project. To ask our self "how much Wikimania costs" we can't only look on the project budget, as the total cost involve also scholarships (from WMF and chapters) and delegations of the chapters and the WMF.
We have tracking pages on Meta about Wikimania 2011http://meta.wikimedia.org/wiki/Wikimania_2011/Budgetand Wikimania 2012 http://meta.wikimedia.org/wiki/Wikimania_2012/Budget (sadly the organizer team of 2012 didn't updated their costs till now...), and I opened a new page for Wikimania 2013http://meta.wikimedia.org/wiki/Wikimania_2013/Budget .
So again, I know to some of you this is too early to put the costs (although the size of the chapters and WMF delegation is known and could be update also now) - but if you can, do it now. If now, remember to do it what you have the numbers.
The data requested is your chapter\wmf delegationhttp://meta.wikimedia.org/wiki/Wikimania_2013/Budget#Delegations and the number of scholarshipshttp://meta.wikimedia.org/wiki/Wikimania/Scholarships/2013your chapters gave.
Thanks, Itzik