i dont think the price is steep at all considering VT is 500 million in the hole. they're not having a party just for the fun of it.  Grace does not make the kind of money they will raise that night just for playing one live show.  and she's obviously gonna do it for free anyway.

i also think there are plenty of people that can afford the tix that are die hard Grace fans.   Kenny Chesney and company are certainly among them, and i'd be surprised if he wasn't in the audience and join Grace onstage for a couple tunes (unless he has a prior obligation that night)