If the nature of any repairs is such that their extent and probable cost cannot be ascertained readily, the solicitation should—

(1) Solicit offers for determining the nature and extent of the repairs;

(2) Provide that upon determination by the contracting officer of what work is necessary, the contractor, if requested by the contracting officer, shall negotiate prices for performance of the repairs; and

(3) Provide that prices for the repairs, if ordered, will be set forth in a modification of the job order.