Waterbending allows you to reduce the cost by by tapping a creature or artifact you control, and you can do this as many times while paying the cost
Thraben Inspector and Inspiring Overseer will both draw you plenty of cards, while Gallant Cavalry will make you lots of creatures
Buying enough packs to get wildcards to craft the current meta's best decks alone can be pricey, and that's ignoring access to drafting events, Mastery Passes, cosmetics and the like
The other way Dual-Ink cards will help is by improving lower-tier decks and strategies
If you're playing a dedicated artifact deck, being able to make extra bodies is great, and if you're playing a dedicated Dinosaur deck, you can get a ton of Treasure tokens to ramp into your high-mana Dinosaurs
This means that, after initially being cast, Kroxa's controller will never be required to pay Commander Tax, as Kroxa can merely be cast from the graveyard.