Depending on how many people are going it may be cheaper to simply rent lanes rather then buying games. Often times with 3 people or more, renting a lane and getting in 2 games will give you you're monies worth, so the more people, the cheaper a game would be. (all dependant on the lanes of course and amount of people going, and number of lanes rented)
I would look into prices for renting a lane for an hour during the times/days we'd be wanting to go. Which may have been discused and I might have missed it.