We look first at Commander (since it's the most played format on tabletop MTG) and Standard (given it's the most popular format in MTG Arena), although of course removal spells that are multi-format staples and show up in Modern, Pioneer, or Legacy will get a nudge
Perimeter Captain Another cheap, white creature you may want to run in your defender decks is Perimeter Captain, due to its ability to gain life when you block with other defenders, on top of being a potential 1-mana 4/4 with the right support cards
The cards that may cost money will have silver (uncommon), gold (rare), or orange (mythic rare) symbols
Disappear (Saga/Legacy/Destiny) Buyback was supposed to be a Tempest Block mechanic, but Disappear borrowed heavily from that block to bring a reusable Unsummon to Urza's Destiny
The cards can be pulled from anywhere in Magic 's 27-year history
Sometimes, it can be a game-winning play to have this card on the battlefield play while you make 5-10 tokens with a big X-spell, not to mention the synergies Corpse Knight has with cards like Elspeth, Sun's Champion and its +1 ability