Similar to the Mox artifacts, Black Lotus costs zero mana, so you can play it on your first turn along side a land, but adds three mana of any one color when you sacrifice it
Outside of their own Loot ability, there are a limitless amount of ways to abuse discard-based abilities like this one
Take, as one cheap and easy example: The Executioner's Capsule
Yes, you could blow most of your budget on picking up Brimaz, King of Oreskos, but he's simply not worth the quantity of great cards you can buy for the same amount of money: Finally, here is the deck with the upgrades: $20 Equipment Upgrade Alright, you know the drill: we're focusing on Equipments, so first we gotta cut cards that go against our theme or are just bad
The bad news is, it isn't always useful, and this card is pretty bad apart from that
buying back spells like Time Warp just sweetens the deal