Your opening hands should prioritize mana and Auras over creatures
The name refers to the near-$4000 pricetag to originally build the deck, though it's a happy coincidence that the deck also features Smokestack
The classic example of this would be Sensei's Divining Top with a Future Sight effect (Mystic Forge is a popular choice) to draw your deck and win with cards like Thassa's Oracle and Aetherflux Reservoir
This card, formerly called "The Onion Knights," depicts the heroes of FINAL FANTASY III
But, replace that Marauding Raptor with an Ashnod's Altar, and suddenly you can sacrifice your eggs as soon as they hit the battlefield, giving you two mana to spend on another egg
Clue tokens seem like a natural fit, since they interact with both halves of the card