Enclosure frame. The most popular material for enclosure frame is 2x4 wood. Industrial aluminum profile can also be used to create modular enclosure. Some builders had great success with frameless enclosure design.
Door and window materials. Plexiglas/acrylic and glass, based on enclosure design. If glass is used it has to be properly framed and adequately thick.
Substrate. The most economically effective for keeper and beneficial for monitor is an organic topsoil/sand mix of 80:20 topsoil:sand proportions. Oak leaf litter can be used on top of it for enrichment.