Family Plan (basic)
5 users, 3 email address per user, 5 gigs each, 5 gigs VPN Plus per month, 2 calendars, 5 gig drive. Include Simple Login as the base plan and the option to add to at least the drive and the VPN per user. And no more than $150 US bucks per year on a 24 month plan. Oh, and the option to port out for when the kids finally leave home.. lol.
I think family plans should start simple. And since the service is security and privacy based. The mentioned limits should be enough for most families to keep their online activities safe. Like email, banking, shopping or plain browsing. And if someone in the family wants more of things like VPN, they could have the option to add at their own discretion.