Grass Zone path
Start with Rot Box at 31 coins (handles up to Level 9). At Level 3, buy Silver Box for 197 coins (Level 15 cap). At Level 6, upgrade to Gold Box for 401 coins (Level 22 cap) which carries you through most of the Grass Zone.
Ice Zone path
When you transition to the Ice Zone, the box meta resets. Snowbox (681 coins) is the entry point. Snowman Box bridges mid-game, Miner Box (1,680 coins) is the steepest single upgrade, and Frozen Box (2,250 coins or 140 Robux) is the end-game option.
Buy boxes in bulk
Before any Epic or Ice Zone late-game hunt, stockpile 10+ boxes of the right tier. Running out mid-route is the fastest way to lose Tong coins and momentum.