Honestly, I don't know off the top of my head how much $$ it will take to earn that many points (also depends on if you play slots, tables or video poker).
But I do know that over our 5 day stay for the convention, I SHOULD at least be able to get one gas card (to drive all my new found chip "treasures" home with)!
If they have a limit of 20 cards (per account), it must not be tooooo terribly difficult.
Just make sure if you come with a spouse, friend, etc that you all play on the same account ....just ask the slot club boothling for several players' cards in your name.