Out of interest, have you tried approaching the University to see if they have funds available to help you out? That would be my first port of call - $500USD isn't much to them.
It certainly crossed my mind, but given financial constraints at the moment I didn't think they would jump on the idea. Also, this is a complete side topic for my real research, so I shouldn't even be doing it. It's tweaked some interest now though so they certainly might be more amenable, if nothing for the good PR.
They're making a big song and dance about being poor, but Universities still have tons of cash sloshing about :)
Fair point though if it's not something explicitly connected with your research - but good thinking about the publicity aspect of it :)
Best of luck with it all - please forgive my non-donation, I'm a student too and, as you know, it's feast or famine and this is the back end of a semester ;)
Out of interest, have you tried approaching the University to see if they have funds available to help you out? That would be my first port of call - $500USD isn't much to them.