Activate Cold Storage's first ability twice by paying 6, exiling Treasure Hunter and Dockside Extortionist from the battlefield.
Activate Cold Storage by sacrificing it, returning Dockside Extortionist and Treasure Hunter from exile to the battlefield.
When Dockside Extortionist and Treasure Hunter enters the battlefield, they trigger.
Resolve the Dockside Extortionist trigger, creating at least ten Treasure artifact tokens.
Resolve the Treasure Hunter trigger, returning Cold Storage from your graveyard to your hand.
Activate ten Treasures by tapping and sacrificing them, adding 10.
Cast Cold Storage by paying 4.
Repeat.
If opponents control eleven or more artifacts and/or enchantments, this combo nets infinite Treasure tokens and colored mana.
This loop relies on recycling your own assets to squeeze massive value out of the opponent's board state. By using Cold Storage to temporarily tuck away both Dockside Extortionist and Treasure Hunter, you set up a clean sacrifice trigger that brings them right back to repeat their entry effects. When Dockside Extortionist floods your side with Treasure tokens, you generate more than enough mana to recast Cold Storage from your hand—retrieved seamlessly by Treasure Hunter along the way—leaving you with a self-sustaining engine that prints infinite mana and tokens.