AT&T family share plan to get that price you have to bring your own phones or get on their Next plan. Which for 3 lines can equal to be $80 more per month  just on the phone payments.. Your verizon phones will not work on their service so you would have to go on Next.

Plus they just put out the More everything plan which gives you discounts if you are on the Edge program(basically the same as AT&T's Next) Which you may be able to upgrade early to. And of corse it is going to be a lot to buy out your contract, you signed an agreement to keep the service for a specific time and by termiating you are going back on your word. Do you even use 6GB? You may be able to lower data for more value. Or if you do, then see about the edge option as it gives you discounts off your line access price.