The key determinants of cost are cycle time, the number of cavities in the mould, material cost and the need for manual operations before or after moulding.
Cycle times for rubber generally range from two to ten minutes, although the cure time for heavy parts may be much longer than this. Reducing the mass of a component not only reduces the material cost, but may also reduce the cycle time. This is especially true for parts with thick sections.
Where zero defects are required, due recognition of process capability is required in order to prevent unnecessary quality inspections after moulding. Checks that are not built into the process will inevitably add to the cost (shortcut to Quality in Rubber).