That was Nick's first fight in the UFC after having been gone for years. Penn was coming off a draw with Fitch and double losses to Edgar. That card also promised Condit and GSP which caused a vacuum.
Nick is a much bigger draw now.
I don't see any circumstances that RR could fight a legitimate top 10 peer in her division as a headliner and draw a million PPV buys. I say top 10 in her division because this excludes stunt bookings (like a 5 year retired actress coming off a loss) It's possible if she's anchored by some other big marquee fight but not with her as the feature.
Nick already has, and most certainly could, pull 7 figure buy rates as a headliner.
how is Nick a bigger draw now? all he has done is lose and not fight.