There is hereby appropriated to the Department of Revenue the sum of $250,000 per annum to be used by said department to pay the expense of its compliance with the provisions of this division and to establish a fund which shall be used by the said department to maintain a program for the equalization of ad valorem tax assessments in this state. Whenever the amount in this fund exceeds the sum of $2,500,000, such excess shall revert to the General Fund of the state. This appropriation shall commence on January 19, 1972. This appropriation shall be over and above any expense incurred by the Department of Revenue in the event it becomes necessary for the Department of Revenue to reappraise any particular county or contract for the reappraisal of any county. Furthermore, the aforementioned appropriation of $250,000 per annum shall be credited against the state’s portion of that expense for carrying out the reappraisal program in each of the several counties of the state. Should it become necessary for the Department of Revenue to reappraise and equalize, or make any contract for the reappraisal and property equalization of any county, the state is hereby authorized to charge the respective county governing body with only that part of the expense which would be the pro rata share normally charged to each local governmental agency of the county; and the state shall contribute its pro rata share, and the same shall be credited against the total expenditure involved for each such county.