You can call it whatever you want. You can call it "new" but only a fool is going to pay you the same $$ for it as they would pay for the same gun NIB.
If I can go to a shop and buy NIB for $700 why would I buy from a individual NIB for $700 unless I am a prohibted person.
Yeah, +1. If you buy the identical item from an individual and have a problem with it you have no recourse. Buying from a shop, I have the manufacturer's warranty and a business that want to make any problems "right". Certainly, those 2 "identical" items do not have the same value.