For a pay as you go account it will cost $349.99 because you won't have a contract. If you go to a normal plan it will cost $99.99 here is the link look at the no commitment pricing its 349.99
http://www.wireless.att.com/cell-phone-service/cell-phone-details/?wtSlotClick=1-002Z3O-0-1&device=Motorola+Backflip%28TM%29+-+Silver&q_sku=sku4380305