This Halloween costume is Master Chief, Spartan 117, the hero from the Xbox 360 game Halo 3. It took some time (my dad helped me a little), but I think it came out great. It got a lot of attention at my school's Halloween Carnival. I'm in sixth grade and this will probably be my last costume so I wanted to make something special.
Step 1: Materials, time, costs
I made this out of cardboard, hot glue, fiberglass fabric, fiberglass resin, spray paint and velcro straps (with help from my dad). The weapon is an old broken Nerf gun that we painted and glued on some PVC piping to make it look more like the one in the game.
We used an old bicycle helmet, (free) broken plexiglass face shield, (free) skateboard knee and elbow pads ($2) from Value Village (second-hand clothing store), old black sweatpants and sweatshirt from Value Village ($4)and some light-emitting diodes (LEDs -- free) that we had around from a racetrack project (we're proud nerds). We also used me dad's cycling gloves, but just velcroed on the fiberglass so they didn't get wrecked.
The fiberglass resin and fabric cost about $30. The spray paint cost $10. These you can get any building supply store (e.g. Home Depot).Everything else we already had and was going to be thrown out eventually.
It took about 20 hours to make. I also earned credit towards my Composite Materials merit badge in the Boy Scouts for this project.