*SPAS-12 Shotgun Example*In terms of actual monetary costs, the cardboard for the SPAS cost 1 dollar. I went to a cardboard supplier and bought the highest quality sheet of cardboard I could find, and make sure the cardboard isn't double-thickness.As well, the gun costs nothing in terms of money, but a lot in terms of time. It took me about 20 hours to make the SPAS.I go about making cardboard guns in a very systematic way. It's simple, it works, but it takes time. Here's how you should go about making cardboard models of complicated objects:Step 1 (Assuming you're making a SPAS 12): Get images of a SPAS-12 Shotgun. Make sure you get all d...