

I'm living in switzerland, and flying to LA is price-wise in the range you've mentioned from here.
the other guys/gals here already gave good answers - I just came across your post & thought I'll write a line.
for me, the rallys I have been have been well worth the spendings. often it's some simple/small things that later turn out to be something important for your further carreer. remember that even still in times of internet etc, nothing beats a personal interaction, at least in my own experience.
at the rally you get plenty of oppurtunities to get in touch with many people. many of them have turned out in something material later for me.
I guess the best recommondation I can give is: come well prepared, ie know what you're doing, what you like to achieve, etc. be open minded & curious.
also, to share room is a good idea - not only money-wise. I shared room twice and both time is has been a great pleasure.
hth
martin