On and after October 21, 1998, notwithstanding any other provision of law, Indian tribal governments may, by appropriate changes in eligibility criteria or by other means, change eligibility for general assistance or change the amount of general assistance payments for individuals within the service area of such tribe who are otherwise deemed eligible for general assistance payments so long as such changes are applied in a consistent manner to individuals similarly situated and, that any savings realized by such changes shall be available for use in meeting other priorities of the tribes and, that any net increase in costs to the Federal Government which result solely from tribally increased payment levels for general assistance shall be met exclusively from funds available to the tribe from within its tribal priority allocation.