I currently have two iphones on an ATT Family Plan. When I try adding a third line on the Apple website it says "Join existing FamilyTalk" for the voice option. It says $60 under it. Will I get charged 9.99 a month to join the voice plan or will it be $60. I am planing on getting the $20 data package and no texts. The total comes out to $80 a month. I was really hoping to get this phone for 9.99 for the extra line and 20 for the data package.