Armor is not necessarily expensive. All you need to get started is some scrap metal, some basic tools, and a good pattern. This pattern library is part of the Armour Archive Web site. It contains most of the patterns I have seen available on the Internet, and is more likely to be working than some other sites.
Our regional SCA chapter maintains this list of Arts and Sciences Links that has a wealth of information on armor, clothes, artwork, and dozens of other topics.