So my phone is finally at it's end and i need a new one. the problem is my phone company is AT&T and the replacement phones are way more than i want to spend and to get the phone i want i have to cancel my contract which would cost me about 140 bucks...blah blah blah. that in mind i thought i could just buy a cheap one on cregs list but i don't know if that would work. will they except a new phone that i have bought? does it have to be AT&T brand? can i still keep my plan and just change my phone? I don't really get the whole thing.