I would like to know the solution to this problem as well.
I think there are few if any good ppc for US market now.
If you want to target the UK or european countries you can use overture UK and espotting. They have quality traffic.
For the US market the good ones are gone (for gambling related ads) and what is around is a bunch of scam ppc’s.
it does not mean that it’s impossible to generate any money, but it’s very hard and implies a very close monitoring and with very odd keywords.
You’ll probably end up spending your $500 without significant players.