You purchase a ticket on your own, and we'll gather afterward in the lobby and walk someplace close by to meet and discuss the performance.
Attending a Sunday matinee show is a good way to preserve Friday and Saturday nights for other events. If you want to take a chance on there being tickets available, Park Square does have a rush line. I believe they're $20 cash, but call to make sure and to gauge potential availability. You could also check for Groupons or whatever.