I really doubt your going to find A Working Xbox 360 For free, I mean where I live I know people sell them for around a $100 or so, but thats the lowest. and $40 or so if broken. (For Parts.)
I'm sorry that you don't have any money for One. but theirs nothing we can do. Maybe you'll win a contest or have a generous someone Donate one to you.
Best of Luck to you
-Mithness