Of course I should add here that I think this should never be done, except for fun!
I like to know the "potential" some times, because I'm often attracted to low-cost box-equivalents that are made by people putting together bunches of unsold packs from opened boxes. I don't usually expect to find obvious packs (like those with thick costume or prop cards) because usually somebody along the way will have tried to cherry-pick the thick or stiff packs.
Sometimes a manufacturer follows a pattern for which packs in a box, or which box in a case, contains the premium cards, even autos. But other times, the first person with a crack at a box might use the brute force method: If there is supposed to be one autograph per box, they will open packs until they find it, then put the remaining packs back in the box for single-pack sales.
Not every seller will have done this, and you're likely to be luckier with opened boxes at a local shop than with a bulk reseller. Though even with a local shop, you might have a customer who riffles through packs (I admit to having done it), or even buys a half-dozen packs looking for a high-end chase card, and stops if they find one. So, your luck is likely to be better the fewer people who've handled the packs before you.
If the manufacturers catered to people who buy single packs, you'd see more redemption cards instead of thick packs. Nowadays the people who go after the thicker items buy boxes, not packs. That may be one reason why you see a few cardmakers producing "mini-boxes" with a lower count of packs for retail outlets.
