i agree with Sarcastic re. now being the cheapest time to buy.. i was looking at NFL Ticket Exchange and StubHub earlier today and i was really surprised at how (relatively) inexpensive tickets are, esp. since i figured Brees' signing would have caused a sharp increase.. If i were you i'd lock some tickets down ASAP.
oh, and whatever you do, don't bother renting a car if you're only gonna be there a little over 24 hrs.. Take a cab from the airport to the Hyatt, and it probably won't be much more expensive than they would charge you to park at the hotel-- plus you'll save yourself a lot of hassle, everything is within an easy walk.