Can I buy the iphone 5s from the at&t store and then cancel it?

So I want to buy the iPhone 5S and I heard that at AT&T they are selling it for $100 now instead of $200 so I was wondering if I could buy it for $200 and then cancel the phone but still have it. So basically i'm asking if I can buy it or $200 and then make it unlocked. Does that make sense?

Yes, you can cancel.

But if you cancel right away you will be charged a huge ETF fee around $350.

They will not unlock it for you if you cancel immediately.

The $100 5S is temporary. Just saying.

As far as doing what you want there's more to it than you may be realizing.

$200 for the phone + activation, voice, text, data plans
then you'd have to wait 2 weeks & then you would have to pay $325 in an early termination fee & then you'd have to let AT&T know to unlock it since its illegal otherwise.

Yes if you pay the cancellation fee.