Yes, selling searched packs in a resealed would be a huge problem. However, unlike LOTR hobby boxes, you can never be sure that you have all the insert cards... with LOTR, once you got one auto card in a box (and oyu usually did), you could be sure that it was the only one. But with HP boxes, sometimes you could get 2-3 inserts in a box or none at all

Playing with your luck I guess. Imagine finding a Weasley costume then selling the rest of the packs and finding out there was a Hermione/chocolate frog card in them
