カードを作るか、もう一パック開けるか

Yes, and it is exact: chasing wins only when the chance per pack is bigger than what one pack brings in divided by what the card costs to make.

At sixteen hundred to make and a hundred a pack, that line sits at six and a quarter in a hundred. Below it, making the card is cheaper; above it, opening packs is.

Much further than people expect, because the average of a chase is not what usually happens to anyone. At one in a hundred per pack the average is a hundred packs, half of people are done by sixty-nine, and being nine in ten sure takes two hundred and twenty-nine.

That is the real argument for paying a fixed price: it buys away the tail, not the average.

Because what a card gives back when destroyed is a fraction of what the same card costs to make, so the exchange is lossy by design. At four hundred back against sixteen hundred to make, one card costs four of its equals.

The page shows that ratio on the first line rather than burying it, because it is the number that decides whether a collection can ever be converted into the cards you actually want.

No, and it cannot. A pack is full of other things that are worth something even when the card you wanted is not in it, and none of that is on this page.

Read the comparison as being about one specific card you have decided you need, which is the situation the question is usually asked in.