The evaluation of activities driving sustainability in the consumer product sphere, such as material recycling and product re-use, often appears to be over-optimistic. Replacement of primary resource production with secondary production, which is the source of most environmental improvements, is rarely evaluated rigorously and is often overstated. Significant progress on measuring replacement has been made in the clothing and related sectors. This study investigates the issue of whether further improvements are possible by introducing factors typically absent, such as the level of environmental burden associated with consumer purchases, and the consumer demand. Via consumer survey and consequent numerical analysis, the work establishes viable metrics to supplement those currently used for replacement. In particular, it is shown that it is not sufficient to simply examine how metrics are constructed; it is also essential to test metrics’ response and sensitivity to input data, from survey and numerical analysis. The metrics developed are shown to be robust and appropriately responsive to changes in key parameters. Operations and decision-making in the sector may be significantly improved by this line of analysis.