That might be good for used items but new mint in sealed box. What is wrong with that.
Nothing, if you're a collector, but I am not. Also, if I was buying it from a LHS or online dealer, nothing wrong with it still in the shipping box. But a previously purchased item to me is used whether it's been out of the box or not and something that is a number of years old and with no warranty all command a lower price.
However (isn't there always?), I recently bought a Williams/Samhongsa 3-rail brass USRA 2-8-2 (Buy Now on E-Bay) for less than $200 to the front porch. It came in the shipping box (but had been taken out to photograph and probably run as well at one time) but looked like new to me. TWO HUNDRED DOLLARS for a BRASS engine...UNBELIEVABLE.
I've been looking for one since I got into O-scale (either didn't have the funds or too late with the offer) and when I saw the price I couldn't refuse, didn't even care if it ran (which it did) as I'm going to modify it into a Seaboard class Q3 Mike.
If it's something that you've been looking for for years I can see making some exceptions.
But I don't buy to just "put it up" in the closet for whatever reason. They're made to be taken out and run.