Since no one bit my Socratic lure, my sequence of answers would have been to point out that SIAI is a charity, charities are nonprofit corporations, corporations keep records of spending, and often make them public; as an IRS-recognized charity, SIAI is obligated to make reports public, and some googling then turns up GuideStar as a source, at which point it's easy to download their PDFs from SIAI and finally answer the question - what does SIAI spend its money own?

I did this earlier for salary information: http://lesswrong.com/lw/2l8/existential_risk_and_public_relations/2ywt There are a lot of interesting things in the filings; I once wrote an essay on what I found in the filings for Girl Scouts: http://www.gwern.net/Girl%20Scouts%20and%20good%20governance (See also Discussion post.)

EDIT: for an analysis of SIAI, see http://lesswrong.com/r/discussion/lw/5fo/siai_fundraising/