Perhaps it makes a sense to look in to a Girls Store from time to time. That's the place, where those new cards show up with 20% discount for sure. Also keep your eye on VG News, to not to miss the new cards.
Another matter is a preview of the shows. If the girl doesn't show up on the carousel, the only chance to see her in action is that tiny non nude preview window in the Store, but its image quality does not stand any criticism - it's just crappy. This is a problem of a long overdue and I really hope that Team will look at this one day, 'cause if the people are ***** to visit the Store more often, they must get a much better picture of the things in there.
Edit: I'm a Diamond member, so you guys might see different prices, depending on your status.