Nix Live money, I like single rebuy
I imagine some players would have issues with $500 live money buy-ins, even if the entry fee were dropped to $500. But, more importantly, the casino won't hold anywhere near the $500 buy-in per player, so the prize pool would be dramatically cut. This option won't fly.
On rebuys, I'm starting to agree with the single-rebuy-only opinion here. Consider the unlimited-rebuy at the Frontier. With the exception of a handful of players who are truly eliminated in round one (usually less than 10!), for everyone else at that tournament, round one is just a way to decide how much in entry fees it'll cost you to get to round 2.
A similar situation when the fees are $1000/$500 could easily cause hard feelings. And it is true that players who are unwilling to rebuy multiple times are at a disadvantage. (That wouldn't be true if rebuys cost the same as the initial entry, but that eliminates the appeal of the rebuy.)
Joe, I think you need to structure a single rebuy round, guaranteed availability if possible. I think you'll get near complete participation in the rebuy round. Players will come in knowing that the event could cost them $1500.