There are at least five or six competitive decks that are quite affordable, such as Goblins, Sligh, Madness, Dead Guys Ale, and Mono Blue Storm, and there are likely even more depending on your starting budget
Set: Sun & Moon: Forbidden Light Type: Fighting Rarity: Rare Retreat cost: Colorless,Colorless,Colorless
It will suck the fight from your opponents and leave them empty husks
Mindbreak Trap (MAR) $20 Mindbreak Trap is a very interesting sideboard card to fight storm combo decks
The physical Japanese version has a full-art SAR with embossed metallic texture
Sure, there are ways to ramp in other colors or with colorless cards, but none seem to offer anything quite on greens level