A county adopting a charter under this chapter may provide for a method of appropriating money for county expenditures other than the method in sections 2, 701 and 702. Any alternative method provided must give the county legislative body the authority to appropriate money, according to the budget, which must first be approved by majority vote of the finance committee. If the budget is not approved before the start of a fiscal year, the county shall, until a budget is finally adopted, operate on an interim budget which may not exceed 80% of the previous year's budget. [1987, c. 737, Pt. A, §2 (NEW); 1987, c. 737, Pt. C, §106 (NEW); 1989, c. 6, (AMD); 1989, c. 9, §2 (AMD); 1989, c. 104, Pt. C, §§8, 10 (AMD).]