Your tech is 'brand new' if it has never been used – or as good as never been used. You may have taken it out of the box then decided it wasn't for you and that's fine.
Whereas something that has been in and out of your pocket or bag is likely to have minor scratches, and so wouldn't be brand new.
Don't worry too much about which option to pick, just go with what you think is best. Once our tech-sperts have had a look, we'll let you know if we're not convinced.
But that also works both ways; if we think it's better than you thought, we'll let you know and pay you what it's worth.