1.20 As part of its value for money appraisal of outsourcing its operations, NS&I prepared a public sector comparator. The Public Sector Comparator estimated the net present cost of continuing to manage the operational service in-house would be £793 million to NS&I over 15 years. NS&I would not have had the resources to modernise its operations. The estimated net present cost of the proposed deal with SBS was £635 million.