Before any discussion with any firm concerning fees may take place, the Executive Director shall cause an estimate of the value of such services to be prepared. This estimate may be based on such factors as a market survey, comparison with fees paid to other departments' or agencies' contractors for similar services, or comparison with the salaries of comparable positions within the Authority, within State service, or within other governmental entities. This estimate shall serve as a guide in determining fair and reasonable compensation for the services rendered. Such estimate shall be, and remain, confidential until approval of contract or abandonment of any further procedure for the services to which it relates. At any time the Executive Director determines the State's estimates to be unrealistic due to rising costs, special conditions, or for other relevant considerations, the estimate shall be reevaluated and modified if necessary.