It doesn't bother me that this is being sold and / or purchased. While it's nothing that would interest me I personally don't see an issue with it being handled the way it is. As has been said here before, better it be cherished by a collector than rotting in an attic.
As well, this item is not necessarily a 'burial box.' Commemorative flags are flown all the time in the US, over state capitals, federal buildings, military posts etc and it is not uncommon for a such a flag to be awarded, in a box, to a citizen. Congressmen and Senators will routinely provide flags that have flown over the US capital to their constituents. All of which are folded into the exact same style of box as the one for sale here. This particular box, even though it has some ribbons (not medals) and a set of rank stripes, does not necessarily mean it was awarded to someone's next of kin.
To me, this no worse or better than dealing in personally awarded medals etc. Whatever floats your boat.