buying and selling iphones

[bhigh8]

I'm sure many of you have done this. what im thinking of doing is using upgrade for iphone5 and selling it. they are going from $800-1100. and then buying new 4s. they are around $450. I'm not sure of how easy this is to do and what i need to know ahead of time. I'm verizon so i need a verizon 4s. but do i open the 5 or just leave it in box?

a 5 is probably better but the difference in money and the fact that i am new to smartphones will make pretty much any phone seem awesome to me.

any help would be great...thanks.

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also, is it worth the trouble? i am hesitant since i have never bought or sold cell phone on ebay.