Warning: Alter game files at your own risk and always make backups! Open the defaultweapon.ini and defaultupgrades.ini files in a text editor. They can be found in bulletstorm/stormgame/config in either your EA folder or STEAM if you have it there.

Now look at ammocost[0]=, ammocost[1]=, unlockchargedammocost=, and unlockweaponcost=. These are all the prices in you'll pay in the shop for a weapon. Simply change all numbers 1 to reduce prices to 1 point a piece.

Changing all the ammopershot[0]= and ammopershot[1]= stats will make your weapons have infinite ammo. Changing rateoffire[0]= and rateoffire[1]= stats will make your weapons fire faster. For example, a good shotgun setting is rateoffire[0]=120 rateoffire[1]=120. Note: [0] and [1] refers to the (normal) and (alternate) fire modes in game.