The per pack math
The basic trade is simple. Retailers usually price boxes below the sum of their packs bought individually, so a box lowers your cost per pack, sometimes substantially. Illustrative example with round numbers. If loose packs run 4.50 each and a 36 pack box runs 130 dollars, the box works out to about 3.61 per pack, roughly a twenty percent discount for buying in bulk.
The discount is real, but it only helps if you were going to open that many packs anyway. A discount on a larger purchase you were not planning to make is not savings, it is marketing. This principle also explains most of the furniture in most homes.
Variance and what boxes do and do not guarantee
Opening more packs smooths your results toward the set's average rates, so a box gives you a less spiky experience than a single pack. It does not guarantee good results, just more typical ones. A box with no top tier hit is a normal outcome for many products, and the box owes you nothing, a sentence we keep having to say.
Some products do carry printed guarantees, like a fixed number of cards at or above a certain rarity per box, and publishers state those explicitly on the product. Anything not explicitly guaranteed is subject to variance. Community tallies can tell you what a typical box of a given product yields, with the usual caveat that those figures are estimates, not promises.
Sealed versus ripping
A box also gives you the option to not open it, which loose packs offer only in theory and never in practice. Sealed boxes of desirable sets have historically sometimes appreciated, which is exactly the kind of sentence that costs people money when they read it as a plan. Sealed prices can stagnate or fall, reprints happen, storage and authenticity questions are real, and none of this is investment advice, because we do not give any.
Our position as a parody church with a compliance streak is this. Buy sealed product to open for fun, or keep a box sealed because owning it makes you happy. The moment a spreadsheet appears, go read about EV and variance first, then buy singles for the cards and index funds for the retirement.
When each one makes sense
Buy loose packs when you want a small dose of the opening experience, when you are sampling a new set before committing, or when a pack is a treat rather than a plan. The per pack premium is the cost of a small portion, like ordering a slice instead of the whole pizza.
Buy a box when the per pack discount applies to packs you genuinely intended to open, when your game's limited format needs the packs anyway, or when you want the smoother variance of a bigger sample. And if what you actually want is two or three specific cards from the set, buy neither. Singles remain the predictable path, and the box remains a box.