Miami is nearly as expensive as NYC.
$750 EF for NBC Main would being in enough new players (due to being more affordable) that you'd be able to keep the $100K prize.
Hell, if you're considering Memphis, I'll toss Indianapolis into the frey. Clean, safe, casinos, great nightlife, Indy 500 Museum, AAA Baseball in one of the finest ballparks in the country, the Canal, great eats, centrally located, and 30 minutes from my home.
I'd also toss in St. Louis.
IMO, you need to have the 4th city be a place that is easy to drive & fly to. It has to have a major airport, and have enough to do to make it a 4 day mini-vacation. I think if you follow this thinking, Miami is out (who wants to drive from northern FL to Miami?
I could list 25 cities I'd want to visit before I got to Memphis, nothing personal.
Maybe keep the NFFC/NBC events at $1300 and add a 3rd event in the $750 range?! You could do this one live/phone/online and bring in tons of new $$$.
2008- Didn't finish last overall in the Classic.
2009- Didn't finish last overall in the Classic or Primetime.