I could see hosts having a similar event to raise money for charity or for a political candidate. However, it does not sound like the hostess in this case was trying to raise money for charity and, if she was trying to raise money for charity, she should have notified her guests ahead of time so that they could decline her invitation.
Had I attended this event, I would have been horribly offended. Not only would my husband and I have left, but I would refuse any invitation from this "hostess" in the future.