C.C.
We have 3 iPhones with unlimited talk/text/data, as well as an international plan, and it's around $280/month. However, if you just had "regular" cell phones, not smart phones, it could be WAY cheaper (as in, whatever your base plan is for phone #1, and then $10 each for phones #2 and #3). We have AT&T and they allow us to share minutes and data among all 3 phones. So if our daughter goes way over on texting, it's no big deal, because the base plan is unlimited, even though adding her phone to the plan is only $10/month for text and voice.