This report summarizes cost adjustment factors for beryllium (Be, S200) and titanium (Ti, 6Al-4V) that were derived relative to aluminum (Al, 7075-T6). Aluminum is traditionally the material upon which many of the Cost Analysis Office, Missile Division cost estimating relationships (CERs) are based. The adjustment factors address both research and development and production (Q > 100) quantities. In addition, the factors derived include optical elements, normal structure, and structure with special requirements for minimal microcreep, such as sensor assembly parts and supporting components. Since booster cost per payload pound is an even larger factor in total missile launch costs than was initially presumed, the primary cost driver for all materials compared was the missiles' booster cost per payload pound for both R&D and production quantities. Al and Ti are 1.5 and 2.4 times more dense, respectively, than Be, and the cost to lift the heavier materials results in greater booster expense. In addition, Al and Ti must be 2.1 and 2.8, respectively, times the weight of a Be component to provide equivalent stiffness, based on the example component addressed in the report. These factors also increase booster costs. After review of the relative factors cited above, especially the lower costs for Be when stiffness and booster costs are taken into consideration, affordability becomes an important issue. When this study was initiated, both government and contractor engineers said that Be was the material to be used as a last resort because of its prohibitive cost and extreme toxicity. Although the initial price of Be may lead one to believe that any Be product would be extremely expensive, the total cost of Be used for space applications is actually competitive with or less costly than either Al or Ti. Also, the Be toxicity problem has turned out to be a non-issue for purchasers of finished Be components since no machining or grinding operations are required on the finished components. Several new costing techniques are developed which provide quantitative measures of the cost of material stiffness, costs related to payload weight, and costs associated with the relative temperature stability of different materials. In addition, use is made of the Design/Cost Trade Model developed by Applied Research, Inc., to determine the booster cost differential relative to changes in payload weight, and a mirror fabrication cost model, developed by OCA Applied Optics, was used for mirror costing. This report is a summary of an extensive study done by the U.S. Army Strategic Defense Command, Huntsville, Alabama.