Ok. I've broken it down every which way. Basically the max subsidy I've ever seen from ATT is $450. Subsidies require 24 months of service. 450/24 = $18.75. This means that $18.75 of your rate repays the $450 and the rest is profit for ATT. So to compare the plans: Add the Data charge + $15 x number of phones + $18.75 x number of phones you MUST upgrade every 24 months. Then compare that total to what you are paying. Example: Old Plan 6GB Mobile Share with 2 smart phones = $160/month And I upgrade both every 2 years New Plan 10GB Mobile Share Value plan with 2 smart phones Data Charge = $100 Number of phones = 2 15*2 = $30 18.75 x 2 = $37.5 New bill evaluated cost = $167.50 The question to ask is if its worth it, in this case for an extra $7.50/mo, for the new plan and extra 4GB of data. There are 2 last figures to consider. 1. There is a trick to saving $36 per phone upgrade or $72 every 2 years. 2. From now until your contract is up you are saving the $18.75 per phone since AT&T is letting on contract members switch.