So I bought a Macbook Pro from amazon and then won a $5,000 gift card to Best Buy . Bought a Macbook Pro from Best Buy and was going to return it new in box to Amazon. I called Amazon and they said they would check the serial number on the outside of the box, but maybe they are wrong. I have installed a ton of stuff on the original one I bought and wanted to keep it. Is there anything on the Macbook that shows it is the same one that came in the box? I feel like I'm actually doing Amazon a favor by returning the unused Macbook instead of the used one. Any advice?