I've never been to the South Point for wagering purposes, but at the West Gate you'll need a players card to put in a wager over 700-1000. Get the bet on the card, and you can wager $3-4000. You can plead ignorance, and see what they will let you bet without a card. I did that for baseball once and hit them for $3000. Getting a players card at all the big casinos is advisable. Even with your card most big wagers have to be approved.
My favorite place to bet for the 2nd Half is the Wynn!