4x8 polystyrene sheets - Model Railroader Magazine

Buying Styrene sheets in 4'x8' offers considreable savings. Typically you can buy a 4x8 sheet for less than a 24"x32" sheet will cost at the local hobby/craft store.
Look in the yellow pages under plastics, commercial. Two of the national companies which have offices in almost all major cities are Allied plastics, (alliedplastics.com) and Laird plastice (lairdplastics.com). These guys will take a non-account "cash" order. They may have a minimum order however.
These companies also custom cut in large runs and may have "drop" pieces of styrene at considerable savings. Ask about this also. These drop pieces are plenty big enough for modeling.
The price of Styrene plastic is going up monthly since it is directly tied to the price of oil (like everything else). However, a 4x8 sheet of .020 styrene should cost about $4.00 (or less). So you can see the savings.