Cash tiers and Gem guns are different purchases
During a run you start on Tier 1 and press V to spend Cash on the next tier. The four tiers are handguns, then shotguns and other medium-range guns, then rifles, then heavy weapons. A pace report says Tier 4 often becomes affordable around wave 20, depending on which monkeys drop Cash. Health is a separate Cash climb on C.
The tutorial offers the first gun of each tier as a freebie. Those defaults are Pistol, Shotgun, Burst Rifle, and Minigun. You do not need a Gem purchase to have a gun when V unlocks the next tier. Gems buy a different gun inside a tier, or upgrade a gun you own. Each Gem upgrade is said to raise that gun's DPS. Per-level upgrade prices are not published.
Listed DPS against the free gun in the same tier
DPS figures below are the published stat, not a new firing test. Rarity labels come from the same catalog pass. A lower DPS number does not describe splash, melee reach, or burst pattern when those were not given.
| Gun | Tier | Access | Listed DPS | Against the free gun in that tier |
|---|---|---|---|---|
| Pistol | 1 | Default | 45 | Baseline |
| Pow Pow | 1 | Tutorial | 87.5 | Best free Tier 1 figure |
| Bayonet | 1 | 2,500 Gems | 83.3 | Below Pow Pow |
| Shorty | 1 | 5,000 Gems | 80 | Below Pow Pow |
| Revolver | 1 | 12,500 Gems | 75 | Below Pow Pow |
| Deagle | 1 | 45,000 Gems | 116.7 | First Tier 1 Gem gun above Pow Pow |
| Dead Man's Hand | 1 | Gunslinger bundle | 200 | Highest Tier 1 figure; also listed as locked |
| Shotgun | 2 | Default | 100 | Baseline |
| El Scorpio | 2 | 15,000 Gems | 160 | Clear step up |
| SMG | 2 | 25,000 Gems, or the gift box | 180 | Above El Scorpio; box skips the Gem price |
| P90 | 2 | 50,000 Gems | 325 | Large Tier 2 jump |
| Burst Rifle | 3 | Default | 185.5 | Baseline |
| AK-47 | 3 | 45,000 Gems | 379.5 | Strong rifle step |
| Longshot | 3 | 50,000 Gems | 400 | Slightly above the AK-47 |
| Katana | 3 | 90,000 Gems | 250 | Below both cheaper rifles |
| Scar | 3 | 90,000 Gems | 525 | Highest Tier 3 figure |
| Minigun | 4 | Default | 605 | Free heavy baseline |
| Laser Cannon | 4 | 250,000 Gems | 700 | Only Tier 4 Gem gun above Minigun |
| Grenade Launcher | 4 | 450,000 Gems | 525 | Below the free Minigun on listed DPS |
| RPG | 4 | Premium, also listed as locked | 480 | Lowest Tier 4 DPS in the table |
How to choose with those numbers
Stay on Pow Pow until you can explain why a Tier 1 purchase should beat 87.5 DPS. Deagle is that purchase, at 45,000 Gems. It is a real spike and a bad first buy while Medic is still locked at 15,000.
In Tier 2, claim the gift-box SMG before paying 25,000 Gems for the same gun. El Scorpio at 15,000 is the cheaper DPS step if you do not have the box yet. P90 is the expensive Tier 2 ceiling.
In Tier 3, AK-47 and Longshot both more than double the free Burst Rifle. Katana costs as much as Scar and lists less than half of Scar's DPS. Buy the katana only if you want the melee weapon itself. The DPS column does not justify it.
In Tier 4, Minigun is already 605 DPS and it is the default. Laser Cannon is the Gem gun that lists more. Grenade Launcher and RPG list less than the Minigun. Their names suggest area fire, but splash damage was not published, so do not pay 450,000 Gems for the launcher on an assumed explosion.
Dead Man's Hand and the RPG are the two locked or premium guns. Dead Man's Hand is tied to the Gunslinger bundle in the DPS article and marked locked in the rarity table. The RPG is called a premium purchase in one list and locked in the other. No Robux price was published for either.
Full obtain lines sit on each weapon entry. Class skills, which often matter more than the next pistol, are on the class pages.