IPHONE QUESTION.. HOW MUCH MORE WOULD I HAVE TO PAY A MONTH IF I ALREADY HAVE THE FAMILY PLAN?

I am due for and ascent and I am meddlesome in removing an iphone but initial i’d similar to to know how most I would compensate monthly for it. I already have a family devise 550min, total texting, and the family interpretation devise for an additional 10 dollars a month. Would I have to compensate anything additional or could this all be enclosed with it?