I understand your argument but people would say that's discriminatory.
Discriminatory?
If you win you must prove you can support yourself in the US, either with money (I think 15.000USD per person and year), or by a job...if you don't have either say good bye to the Green Card!!...thus if you don't have the 500 bucks to apply, what are you doing the day of the interview???
I don't see any discrimination here..