The only thing I know of is vacuum formed plastic, which is what they use in the 501st legion. It looks nicer, lasts longer, and is a lot more resilient, but it's about 6 times more expensive at the very least, not to mention way more time consuming, and considerably more dangerous, since the machine can spontaneously ignite if you mess up, and there's a lot more poisonous chemicals involved. I'd stick to pepakura if your going for low cost and safety. If pepakura is too expensive, buy the supplies individually over time, when you're done with one tep of the process, then you buy the supplies for the next step. Or you could borrow as much of the stuff you need from neighbors or relatives. But if the vacforming sounds better, go for it, just make sure you know exactly what you're doing.