You will need 36 rolls of plaster bandages (rolls are typically 6 inches [15cm] wide and 4.5 yards [4.5 M] long).

I purchased 3 cases of 3M Medical Bandages from FXWareHouse Inc. My three cases cost me $138.00 total with shipping (1998 prices). I recommend "shopping around" for the best price possible, and for the best bandage possible. medical Bandages are usually more impregnated with plaster than artist/craft bandages. I hear that M-PAct brand bandages are pretty good (circe 2007) but I have not personally tested that brand.

Large Bowl. Plastic or glass. This will be used for wetting the plaster bandages.
Thick dish washing gloves for fiberglassing. Do not use thin MEDICAL gloves... the fiberglass just rips them apart once it solidifies.
Fiberglass Mat. It is a course material, thick in padding, looking sort of like "shredded wheat cereal". This is used as a strengthener under the fiberglass cloth. I recommend buying at least 48 sq. ft. worth of Mat.
Fiberglass Cloth. This is a finely woven mesh that looks like polyester cloth. But be warned this is not a normal fabric. This cloth was designed to be super absorbent. Do not get these or the FIBERGLASS MAT wet. They will greatly lose their absorbent properties after being exposed to water. I recommend buying at least 48 sq. ft. worth of Cloth. $7.00 per mat.
Fiberglass Resin. I recommend getting 3 gallons worth of resin. They run about $28.00 a gallon at the stores in my area. I also recommend buying 4 additional tubes of hardener. The resin usually comes with the right amount to cure the fiberglass... but I always over pour. Get extra hardener just to be safe.
Medium Sized bowl. Prefereably plastic. This will be used for mixing the fiberglass resin and will probably be unusable afterwards.
A Tarp or water proof Drop Cloth. Plastic sheeting works well too.
All in all the cost of the fiberglass cost me about $250.00USD (1998 prices). Look around for the best price on supplies. I used HOMEDEPOT for purchasing my fiberglass supplies. Hardware stores are usually more pricey than most places but I did this on a whim and didn't plan it very well.

Combining my cost of the fiberglass with the $138.00 for the bandages and taking all my workers out for dinner... MY accurate sized Body Cast cost me $425.00 (USA prices in 1998).

Price Adjustment 2006: Bandages = $162.00 Fiberglass = ?