Budget Commander: Zada, Hedron Grinder | $25, $50, $100 This article is is a long time coming
Being an artifact, you can also abuse Manascape Refractor with cards like Unwinding Clock and Clock of Omens for maximum value
It only sees play in one major deck, but it is the defining card of the archetype and what makes it work
If you play older Historic on Arena, you know just what this can do with Scurry Oak, but its also best buddies with Walking Ballista
The key creatures may not look fast, but Hedron Crab and Ruin Crab will mill cards with shocking efficiency
Build up a strong enough board presence, or get your opponent low enough with chip damage, and you can create a game state where your opponent can't even kill your creatures without risking death themselves