Ok so i want to buy this phone online unlocked and use my pay as you go cards from at&t. Will this work. Its gsm band Is 850 and i heard i could get any phone unlocked with 850 and 1900 and use at&t. Is this true . If not lead me in the right direction. I dont have credit so i can only buy phones at full retail price unlocked and use them. And id prefer at&t since i can use the pay as you go cards which is easier. Thanks