I wouldn't worry too much about the extra shirt and bag that come with the boundary line and 3 game packs, the shirt isn't even the official members polo, its just a cheaper looking version with one logo and the bag is pretty much something that you wouldn't pay more than a few dollars for anyway.
I guess 3 game members pay nearly $30 a game in the standing area and no Sydney or Showdown access while 11 game GA members pay closer to $20.
Also worth noting that more of the money from the memberships go to the club compared to the purchase of a ticket for individual games.