Comment by rtkwe

Some formats, but you can always play sealed which removes the ability to bring in outside cards at all. You either get your own pool of cards or draft from a shared pool so it's more down to your skill in building a deck (or luck pulling the right card from a pack you opened or it getting passed to you because the player before you didn't need it and wasn't drafting for value).

There's cheaper strategies in most formats though that you can still get wins with, Red Aggro decks are usually pretty cheap to build and have a decent win rate. You'll rarely place highly in tournaments with it but that's true for most people and most decks.