Buying a weapon is the cheap part. The 
ShotgunShotgunCosts$150Sold onIsland 2+Damage maxed700 costs $150 and its
ladder costs $26,540. The 
KnifeKnifeCosts$45Sold onIsland 1+Damage maxed120 costs $45 and its ladder costs
$76,732.
Every upgrade with its price, station and island
What a point of damage costs on each weapon
| Weapon | Price | Damage at base | Damage maxed | Damage per second | Cost to max | Cost per point gained |
|---|---|---|---|---|---|---|
| Brass Knuckles | $24 | 5 | 60 | — | $64,278 | $1,169 |
| Knife | $45 | 16 | 120 | — | $76,732 | $738 |
| Pistol | $50 | 25 | 160 | 1,067 | $26,855 | $199 |
| Shotgun | $150 | 75 | 700 | 3,182 | $26,540 | $42 |
| SMG | $650 | 24 | 70 | 1,400 | $21,469 | $467 |
| Sniper Rifle | $3,800 | 200 | 500 | 500 | $35,749 | $119 |
| Assault Rifle | $20,000 | 40 | 100 | 1,429 | $30,550 | $509 |
The last column is the honest comparison: total ladder cost divided by the damage the ladder
adds. The ShotgunShotgunCosts$150Sold onIsland 2+Damage maxed700 wins by a wide margin because each upgrade step
raises all 25 of its pellets at once.
Where each ladder gets expensive
Upgrade steps are not evenly priced. Most ladders are cheap for the first half and then climb steeply, so there is usually a sensible place to stop.
| Tier | Damage per hit | This step | Spent so far | Relative step cost |
|---|---|---|---|---|
| Base | 75 | — | $0 | |
| 1 | 100 | $20 | $20 | |
| 2 | 125 | $30 | $50 | |
| 3 | 150 | $40 | $90 | |
| 4 | 175 | $200 | $290 | |
| 5 | 200 | $250 | $540 | |
| 6 | 225 | $300 | $840 | |
| 7 | 275 | $1,500 | $2,340 | |
| 8 | 325 | $2,500 | $4,840 | |
| 9 | 375 | $3,000 | $7,840 | |
| 10 | 500 | $4,240 | $12,080 | |
| 11 | 600 | $6,120 | $18,200 | |
| 12 | 700 | $8,340 | $26,540 |
The shotgun’s early steps are trivial and the top of the ladder is where the money goes. Because each step is worth 25 points on target, though, even the expensive steps stay good value.
| Tier | Damage per hit | This step | Spent so far | Relative step cost |
|---|---|---|---|---|
| Base | 200 | — | $0 | |
| 1 | 210 | $140 | $140 | |
| 2 | 220 | $220 | $360 | |
| 3 | 230 | $349 | $709 | |
| 4 | 240 | $690 | $1,399 | |
| 5 | 250 | $900 | $2,299 | |
| 6 | 260 | $1,400 | $3,699 | |
| 7 | 270 | $2,000 | $5,699 | |
| 8 | 280 | $2,650 | $8,349 | |
| 9 | 300 | $3,300 | $11,649 | |
| 10 | 350 | $5,600 | $17,249 | |
| 11 | 400 | $8,500 | $25,749 | |
| 12 | 500 | $10,000 | $35,749 |
The sniper’s last three steps cost $5,600, $8,500 and $10,000, which is more than the whole lower half of the ladder. They take it from 300 to 500 damage a shot, and that only matters against the two largest bosses.
The melee ladders are the longest
KnifeKnifeCosts$45Sold onIsland 1+Damage maxed120 and 
Brass KnucklesBrass KnucklesCosts$24Sold onIsland 1+Damage maxed60 each have 16
steps, three more than any firearm. They also start at a few dollars, which makes them the only
upgrade path that is meaningful on island 1.
| Tier | Damage per hit | This step | Spent so far | Relative step cost |
|---|---|---|---|---|
| Base | 5 | — | $0 | |
| 1 | 6 | $8 | $8 | |
| 2 | 7 | $16 | $24 | |
| 3 | 8 | $34 | $58 | |
| 4 | 9 | $60 | $118 | |
| 5 | 10 | $90 | $208 | |
| 6 | 12 | $160 | $368 | |
| 7 | 14 | $220 | $588 | |
| 8 | 16 | $480 | $1,068 | |
| 9 | 20 | $710 | $1,778 | |
| 10 | 25 | $1,600 | $3,378 | |
| 11 | 30 | $2,800 | $6,178 | |
| 12 | 35 | $6,200 | $12,378 | |
| 13 | 42 | $13,200 | $25,578 | |
| 14 | 50 | $16,700 | $42,278 | |
| 15 | 60 | $22,000 | $64,278 |
The first five steps together cost $208 and take the damage from 5 to 10. That is the best money on the first island by a distance, and it is why brass knuckles carry an early run.
Where to stop
Rules of thumb Finish the shotgun ladder; every step pays for itself. Take the sniper to 300 damage and stop unless you are going after the final boss. Upgrade melee only while the steps are still cheap, which is roughly the first half of the ladder.
Attachments are priced per weapon
The attachment bench does not charge a flat rate. Each weapon carries its own price list, and
the spread between them is large: a Compensator is $220 on the
ShotgunShotgunCosts$150Sold onIsland 2+Damage maxed700 and $3,000 on the 
Assault RifleAssault RifleCosts$20,000Sold onIsland 5+Damage maxed100.
| Attachment | Pistol | Shotgun | SMG | Sniper Rifle | Assault Rifle |
|---|---|---|---|---|---|
| Red Dot Sight | $310 | $280 | $460 | $640 | $5,500 |
| Sniper Scope | $940 | $650 | $940 | $1,200 | $4,300 |
| Compensator | $400 | $220 | $600 | $500 | $3,000 |
| Suppressor | $2,500 | $1,800 | $2,500 | $2,500 | $8,000 |
| Laser Sight | $100 | $140 | $280 | $1,600 | $4,800 |
| Extended Mag | $90 | — | $320 | $1,200 | $5,400 |
None of them add damage. Sights and the laser change how easy a weapon is to aim, the barrel attachments cut recoil, and the extended magazine buys you shots between reloads. Fitting all of them to one weapon is its own achievement.
The bench opens on island 2 with only the Laser Sight. Island 3 adds the Red Dot Sight, the Compensator and the Extended Mag; the Sniper Scope and the Suppressor arrive on island 4.
The extended magazine
The magazine is the one attachment with a clear rule attached. It adds no damage, so it is worth buying only when reloading is what is costing you the fight.
The ShotgunShotgunCosts$150Sold onIsland 2+Damage maxed700 has no extended magazine at all: it holds two shells and
that never changes.
The boat motors and the radar
The boat arrives on island 1 as a quest reward and comes with a motor already fitted. Two upgrades replace that motor, and a radar can be bolted on separately.
| Upgrade | Price | Thrust | Against the starting motor | Sold on |
|---|---|---|---|---|
| Starting motor | Comes with the boat | 800 | 100% | — |
| Big Motor | $230 | 1400 | 175% | Island 2, 3, 4, 5 |
| Dual Motors | $860 | 2000 | 250% | Island 4, 5 |
| Boat radar | $200 | — | — | Island 3, 4, 5 |
The first upgrade is the good one. It costs $230 and takes the boat from 800 thrust to 1,400, which is a 75% increase for the price of a few Standard Lure catches.
The second costs $860 and takes it from 1,400 to 2,000. That is a 43% gain over the motor you already have, for nearly four times the price of the first upgrade.
If you buy one thing Buy the first motor as soon as you reach island 2. It is the cheapest meaningful quality of life purchase in the game. Leave the second until money stops being a constraint.
The boat radar
The boat radar (not the handheld Radar tool sold in every shop) costs $200 and appears in the shop from island 3.
Unlike the motors it is not a speed upgrade, so the two decisions are independent. If you are losing time working out where to go rather than getting there, the radar is the fix.
Where to buy them
The first motor is stocked from island 2 onwards, the second only from island 4, and the radar from island 3. None of the boat parts is removed from a shop once it appears, so there is no window to miss.