Quickest way to get styrene in my opinion is Walmart. Go to the "for sale" signs and there you go $0.92/piece for a sheet of styrene. Just use the white part for the outside, and you can glue pieces together to get the thickness you want. Also, for cheap plastic tubes, look into crazy straws (the multi-colored 8-pack of hard straws), and various types of stick pens you can get in the 10-15 for $1 pack.