3x5 index card binder Rite in the Rain All-Weather Wallet Kit 991T-KIT jotting down notes and so much more SHANGRLA 3x5 Index Card Holder

3: Target creature gets +X/+X or -X/-X until end of turn, where X is the number of Swamps you control

We waste our first turns mana a good chunk of the time anyway, so the opportunity cost is even lower than it appears on the surface

For this example we're using Light-Paws, Emperor's Voice, a monowhite commander who wins by stacking up a pile of buffs and then inflicting commander damage (a Voltron build)

Options include: Mana Crypt, Ancient Tomb, City of Brass, Grand Coliseum, Nomad Stadium, Tarnished Citadel, Mana Vault, Karma, Royal Decree, Ankh of Mishra Mana Crypt is a very affordable $4 online, but the physical copy, eh, not so much ($150)