If you do, at the beginning of the first upkeep, each opponent loses 3 life, then you gain life equal to the life lost this way
TCGPlayer is the other obvious option, and it's a great marketplace
Second, I'll use this moment as a reminder that Core (Bracket 2) is on the level of an average, modern-day preconstructed Commander deck, but that doesn't mean there can't be some variance there
The Enchanted Cards also are not only just the rarest type of print, but they are alternate art of other cards that are available
The first (and probably obvious) method is by just buying them from the official in-game store
While there are ways to make the most popular decks in the format more unique like running Tap/Untap matters Lathril, Changelings Ur-Dragon, or running a mostly Orzhov Edgar deck with a budget manabase by and large these decks play out the same way every time