In addition to finding them around the map, or receiving them from other characters for specific missions, Grand Theft Auto IV's Weapons can be bought from a few different places. There are three underground gun shops on each of the three main islands of Liberty City. You can also use Little Jacob as a source for guns and ammo once you've gotten his friendship statistic over 80%.
In the Lost and the Damned, you can call Terry Thorpe for weapons, and in the Ballad of Gay Tony, Armando Torres. Aside from a few differences, they sell weapons as the same price as Little Jacob.
WARNING: If you use up ALL the ammo for a weapon, Niko will drop the weapon and you cannot pick it back up. This can be pretty costly if it is an expensive weapon, so make sure that you do not fire the last round of ammo for a particular weapon if you do not want to lose it.
Melee
| Weapon | Cost | Notes | |
|---|---|---|---|
| Gun shop | Little Jacob | ||
| Baseball bat | $5 | N/A | |
| Knife | N/A | $100 | |
Firearms
| Weapon | Rounds per Magazine | Max. rounds | Gun cost | Ammo cost (Magazine) | Notes | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Gun shop | Little Jacob | Terry | Armando | Gun shop | Little Jacob | Terry | Armando | ||||
| Pistol | 17 | 1500 | $600 | $420 | $420 | $420 | $35 | $25 | $25 | $25 | |
| Combat Pistol | 9 | 1500 | $1500 | N/A | N/A | N/A | $100 | N/A | N/A | N/A | Unlockable after mission Museum Piece |
| Automatic Pistol | 17 | 1500 | N/A | N/A | $500 | N/A | N/A | N/A | $15 | N/A | |
| 44 Pistol | 8 | 640 | N/A | N/A | N/A | $640 | N/A | N/A | $50 | ||
| Micro SMG | 50 | 1200 | $1200 | $480 | $480 | $480 | $100 | $20 | $20 | $20 | |
| SMG | 30 | 1200 | $2500 | $1750 | $1750 | $1750 | $130 | $20 | $20 | $20 | |
| Gold SMG | 30 | 5000 | N/A | N/A | N/A | $5000 | N/A | N/A | N/A | $60 | |
| Assault Rifle | 30 | 570 | $3500 | $2450 | $2450 | $2450 | $80 | $55 | $55 | $55 | |
| Carbine Rifle | 30 | 570 | $5000 | $3500 | $3500 | $3500 | $100 | $70 | $70 | $70 | |
| Pump Shotgun | 8 | 72 | $1200 | $840 | $840 | $840 | $100 | $70 | $70 | $70 | At some point, Little Jacob Will switch to selling the Combat Shotgun instead of the pump shotgun |
| Sawn-Off Shotgun | 10 | 70 | N/A | N/A | $600 | N/A | N/A | N/A | $600 | N/A | |
| Combat Shotgun | 10 | 70 | $2500 | $1500 | $1500 | $1500 | $200 | $100 | $100 | $100 | |
| Assault Shotgun | 8 | $3500 | N/A | $3500 | N/A | $25 | N/A | $25 | N/A | ||
| Sniper Rifle | 5 | 42 | $6000 | N/A | $5000 | N/A | $800 | N/A | $500 | N/A | Unlocked after mission Luck of the Irish |
| Combat Sniper Rifle | 10 | 40 | $8500 | $5000 | $5000 | $5000 | $500 | $500 | $500 | $500 | |
Explosives
| Weapon | Max. in inventory | Weapon cost | Ammo cost | Notes | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Gun shop | Little Jacob | Terry | Armando | Gun shop | Little Jacob | Terry | Armando | |||
| RPG | 8 | $15000 | N/A | $10000 | $10000 | $5000 | N/A | $300 | $300 | Unlocked after Babysitting |
| Grenade | 25 | $1000 | $700 | $700 | $700 | $1000 | $700 | $700 | $700 | |
| Molotov | 25 | $500 | $350 | $350 | $350 | $500 | $350 | $350 | $350 | |
| Pipe Bomb | 25 | N/A | N/A | $700 | N/A | N/A | N/A | $700 | N/A | Only in Grand Theft Auto: The Lost and Damned. |
| Sticky Bomb | 25 | N/A | N/A | N/A | $800 | N/A | N/A | N/A | $800 | Only in The Ballad of Gay Tony |
| Grenade Launcher | 25 | N/A | N/A | $7000 | $8000 | N/A | N/A | $700 | $300 | Only in The Lost and Damned and Ballad of Gay Tony. |