A nylon jacket or a plastic poncho is a cheaper alternative but the downside is that these materials trap moisture which makes it more difficult for your body to regulate temperature.
Your outer shell layer protects you from elements. The best material for your outer shell layer is Gortex which is both breathable and waterproof. A nylon jacket or a plastic poncho is a cheaper alternative but the downside is that these materials trap moisture which makes it more difficult for your body to regulate temperature.