2.33 While PITO challenged Mason Communications about some of the quantities input into the comparator, PITO did not analyse in detail why the cost of a conventionally procured national radio system was more expensive than the cost calculated in the should-cost model. Removing cost indexation, risk allowances and cost contingencies from the comparator reveals that the cost base of the comparator was £1,260 million (see Figure 11), £270 million more than the cost base of Airwave as calculated in the should-cost model. However, PITO had tasked Mason Communications to design a comparator to give an equivalent service to that of Airwave - not to replicate the system design. There were, therefore, inevitably many design differences. While this made any meaningful like-for-like comparison between the two systems impractical, a more detailed investigation of the cost difference might have provided greater confidence that the comparator was the most cost-effective traditionally procured system offering an Airwave equivalent service.