What does the iphone plan cost so much?

So I have ATT and I'm currently eligible for an upgrade. I want to get the new IPhone 5 but when I tried to order it on Apple.com, it said that my plan would be $70 a month for talk and $30 a month for data. Since when did you have to pay $100 a month for your IPhone plan. That's outrageous! I checked the plans for the IPhones 4 and 4s and they were the same. Can someone please explain this to me?

Added (1). There are three iphone 4's (not 4S's) on my family ATT account all currently paying $30 a month.

I pay $40 unlimited everything, simple mobile on my iphone 5

Well if you don't talk that much then only get like 100 minutes a month and AT&T does have rollover minutes so what you don't use that month goes to the next month. But their plans are a little pricey my dad pays 106 between the two of us

You need to look at individual plans. $40 for calling, $20 for data… $60/month.

They got rid of their $5 / 200 msg plan I see, that sucks because I use that since 200 msgs is great when all imsgs are free… Can also use an app instead like voxer but your friends need to install the app too.