I know it's possible for it to be done but I just cant, as alt fire does not work and it still refuses to change with spike in my inventory, I'm a little lost at this point.

I have one expensive gun skin for each gun in the game. As of right now I don't feel the need to ever buy a gun skin again because I will always be using a nice skin when I buy a gun. However, like many others have pointed out, I would if I...