Just an update: as of two nights ago, the large conference room at the MSP "C" WorldClub (holding 7+ people) costs $65/hour if you're a WorldClub member and $90/hour if you're not, plus you'd have to buy a $45 day pass to get into the club to use it (although your guests wouldn't have to buy anything, regardless of their membership status).

The smaller 4 person conference room runs $45/hour if you're a member or $65/hour if you're not, and then you would also have to buy the $45 day pass.