The figure I have quoted of $2.5 billion is totally accurate. Well sort. The exact amount is $2,483,300,000. Your link says it also.
IRAQ RELIEF AND RECONSTRUCTION FUND
(INCLUDING TRANSFERS OF FUNDS)
For necessary expenses to carry out the purposes of the Foreign Assistance Act of 1961 for humanitarian assistance in and around Iraq and for rehabilitation and reconstruction in Iraq , $2,483,300,000
, to remain available until September 30, 2004, including for the costs of: (1) water/sanitation infrastructure; (2) feeding and food distribution; (3) supporting relief efforts related to refugees, internally displaced persons, and vulnerable individuals; (4) humanitarian demining; (5) healthcare; (6) education; (7) electricity; (8) transportation; (9) telecommunications; (10) rule of law and governance; (11) economic and financial policy; and (12) agriculture: Provided, That these funds shall be apportioned only to the Department of State, the United States Agency for International Development, the Department of the Treasury, and the Department of Health and Human Services, as appropriate, for expenses to meet such costs: Provided further, That with respect to funds appropriated under this heading in this Act or proposed for appropriation in subsequent Acts, the responsibility for policy decisions and justifications for the use of such funds shall be the responsibility of the Secretary of State and the Deputy Secretary of State and this responsibility shall not be delegated: Provided further, That funds appropriated under this heading shall be used to fully reimburse accounts administered by the Department of State and the United States Agency for International Development, not otherwise reimbursed from funds appropriated by this chapter, for obligations incurred for the purposes provided under this heading prior to enactment of this Act from funds appropriated for foreign operations, export financing, and related programs: Provided further, That the United States may accept from any person, foreign government, or international organization, and credit to this Fund, any contribution of money for such purposes: Provided further, That funds appropriated under this heading shall be available notwithstanding any other provision of law, including section 10 of Public Law 91-672 and section 15 of the State Department Basic Authorities Act of 1956: Provided further, That funds appropriated under this heading that are made available for assistance for Iraq shall be subject to the regular notification procedures of the Committees on Appropriations, except that notifications shall be transmitted at least 5 days in advance of the obligations of funds.