The other thing that EnglandFans do well is that to get your credit (similar to what Arsenal are doing in Belgrade) you have to go to a city centre location/stadium with ID and get physically get your credit. Or else you can email your flight ticket/hotel booking to them (as used by the Scousers also). This way only people who have actually been get the credit which I think is the right way to go.
I know it does stop people with less money from going to the big games but sadly you can't really go to any games these days without money. I have almost completely (Shaktkhar to see Edy aside) stopped going to home games to save money. I am going to about one away game every couple of months to keep my credits up + funnily enough I like going to games.
Personally I am not a fan of people buying tickets and selling them just to gain the credit but I also appreciate certain fans (like those coming over from the States just to watch a game) do benefit from this procedure.