New Magic players almost all make the same costly error, and it feels like the natural thing to do: they buy packs to get cards. Opening a booster is genuinely fun — the gamble, the reveal, the chance at something great. But if your goal is to build a specific deck, buying packs to assemble it is close to the worst-value way to spend money in the entire hobby, and the maths is brutal once you actually look at it.
Why packs are a bad way to get cards
A booster pack is a randomised handful. The specific cards your deck needs are a tiny fraction of all the cards that could be in those packs, so to get the few you want you must open many packs and end up with a huge pile of cards you do not need. You are paying, over and over, for the cards you are not after in order to occasionally hit one you are. As a way to acquire known cards, that is gambling with extra steps, and the house — the randomness — always wins.
When packs are still worth it
Packs have their place: the social ritual of opening them, the format of limited play where opening and building on the spot is the whole game, and the simple pleasure of the gamble if you enjoy it for its own sake. None of that is wrong — just be honest that you are buying entertainment and a lottery ticket, not efficiently acquiring cards. If the goal is a particular deck, that goal and pack-opening are different activities.
The takeaway
Separate the two impulses. If you want the fun of opening packs, open packs and enjoy them as the gamble they are. If you want to build a deck, buy the singles you need and skip the lottery. New players who learn this early save astonishing amounts of money and get better decks faster. Singles are not a cheat code; they are just the sane way to buy the cards you already know you want.