So, I went to WalMart and bought 3 yards of green fabric. I then sewed this fabric onto a bicycle helmet to make the helmet. I then took an old brown shirt, cut off the sleeves, and resewed the green fabric on the interior making the vest in the picture. Most of the other clothing I found either on Amazon.com or Goodwill for $3-5 each.
I went to the firing range and got an empty shotgun shell to rubberband to the helmet. The other shotgun shells on the sash were 1/2" PVC pipes I cut and then wrapped in red electrical tape.
I did have to buy some liquid latex which was pretty expensive at about $10. I used children's playdough/clay I got at walmart for $2-3 to sculpt a lower lip and nose. Then I just bought a toy shotgun, and some very brown foundation/makeup.
It took me a few tries to get it right, as this was my first time doing any sculpting, makeup, or latex work. As you can see in the 4th pic. My first time mocking up the costume made me look like the Nutty Professor.