Pistols have a chance of appearing with a laser sight both in the store and in the hands of enemies. Likewise, SMGs, Shotguns, and Rifles (and the revolver pistols) have a chance of showing up with either a guiding laser, a scope, or both. However, it is fairly uncommon to find a weapon featuring both a scope and a guiding laser. Most pistols and SMGs can also come with suppressors, although this makes no change to the price and only changes the firing sound of the weapon.
Pistols, SMGs, Shotguns, and Rifles come in three colors: black, chrome, and gold. One way to get the gun you want is to start a stage (at any point of your arena combat career) and immediately exit back to the main menu. Once back at the main menu choose to continue your arena combat career. This will take you back to the prep screen with no impact on your progress and, more importantly, refresh the store's inventory. With a little luck you can nab that elusive gun in the color you want. Counting the base model weapons, all their variants, and color combinations there are at least 443 possible weapons to purchase.
List of Weapons
Below are lists of all of the different weapons that are used in the game. Weapons shaded in lighter-grey can only be used in the Story Mode and are unavailable for purchase in Arena Combat Mode. Weapons shaded in red cannot be legally used by the player at all.