Automail arm for Edward Elric cosplay!?

im cosplaying as ed elric from Full Metal Alchemist and i have the wig and the red coat with the shirt and pants with gloves and pocket what, but im missing the automail arm! i dont know what to do cuz online its like $250 and i dont have money like that cuz my family is very poor and i dont know how to make stuff very well so if anyone can give me a website for an automail arm for under $100 i would be most appreciative! oh and if u kno houw to make it from scratch tell me a website for how to make it BUT NO PAPER MACHE! I CANT DO THAT! haha i tried -.-'' so please help! and keep in mind that I ONLY HAVE $150!!