The government contracted discounts are quite significant. Before CWT beat them, Qantas Business Travel (QBT) had the contract. They would discount all published fares by 7%, 9% for BA and 18% for QF. QF increased to 20% when it was renegotiated and FF pts were no longer awarded. For a *ONE* fare, the sectors were all prorated so if the itinerary was composed of predominantly QF flight numbers, the overall discount was near the full 20%.
Based on responses so far, sounds like no agent will/can come close to these discounts.