What the Knife is good for
The Knife is the Island 1 boss weapon, because no guns are sold there. It also farms small catches without ammo.
Knife upgrades: sharpening at the anvil
It costs $45 at the Lighthouse shop. The anvil next to the shop sharpens it: the first three sharpenings cost $14, $28 and $36 and take it from 16 to 22 damage per hit.
Each step costs more than the last; the Lighthouse shop goes to level 3, and later islands sell more.
Knife vs Brass Knuckles
Against Brass Knuckles (5 per hit) the Knife is more than three times stronger for $21 more. Fully upgraded it reaches 120 per hit.
Game8 ranks it A, and a long-form ranking calls it the best value after sharpening.
| Price | Damage | Tier | |
|---|---|---|---|
 Brass Knuckles | $24 | 5 per hit (60 fully upgraded) | C (Game8 tier list) |
 Dynamite | $25 per stick | 200 per blast (area) | B (Game8 tier list) |
Tier letters are an opinion from a published tier list, shown with the numbers that back or contradict them.