I want an iPhone 4s but don't want to pay alot monthly?

We have a family plan with 4 dumb phones through Verizon. I want to upgrade to an iPhone 4s. I would leave the plan but it seems stupid when they charge you 45 for the phone a month plus the cost of the phone. What will it cost to stay on the family plan just to add the iPhone?

They will charge you an extra 30 dollars a month for the data, along with whatever you are already paying for your minutes and texting. The data package is required when you buy the phone.