Apple have a great no-questions-asked return policy for 14 days.
if you still have any misgivings by the time it arrives, you can aways send it back for a full credit and order same model with 8gb memory
(which is what I'd be doing. makes it easier to sell, come the time)
in fact you could even use it for a few days before packing it up to return, which'd lessen the time you'd be without one, assuming you have the spare $ to effectively pay for 2 until Apple credit your a/c with the $ for the 1st one.
if you still have any misgivings by the time it arrives, you can aways send it back for a full credit and order same model with 8gb memory
(which is what I'd be doing. makes it easier to sell, come the time)
in fact you could even use it for a few days before packing it up to return, which'd lessen the time you'd be without one, assuming you have the spare $ to effectively pay for 2 until Apple credit your a/c with the $ for the 1st one.