The Tax Assessor/Collector of Bibb County, respectively, shall be responsible for the budgetary operations and functions of his or her office. The expenses of the office shall be financed on a pro rata share basis from the proceeds of any state, county, and municipal ad valorem taxes collected in the county in the same manner as the salary of the tax assessor/collector is paid pursuant to Section 40-6A-2. Any funds retained by the office pursuant to this section shall be used solely for the operation of the office, respectively, subject to approval of the budget for the office by the county commission in the same manner as the budget is currently approved.