While waiting for the second show, I was chatting to the gentleman across from me, and asked him how he came to be at the show.
Seems he was there through a service called Audience Extras that is a resource for filling empty audiences. For an $85 annual fee members are put on a list for arts events willing to fill up extra seats. Individual reservations to these events are $3.50. Golly, that makes the GoldStar 50% off seem pricely!