The formula-driven approach to arriving at a 'Net TOC' included adjustments for the very factors that - in the opinion of NZTA - define value. The lower of the two Net TOCs would therefore, by definition, represent the maximum prospective value for money.
The estimate for the 'specimen design' prepared by the NZTA served as a comparative TOC, providing information from which to verify VfM. The estimate proved helpful to the proponents as a cross-check, and in NZTA's opinion did not influence the proponents' development of the TOC.
NZTA did not engage an Estimator for the selection process, relying instead on the competitive forces of the process.