Other provisions of law to the contrary notwithstanding, beginning January 1, 1998, the collector of revenue in a city not within a county shall receive an annual salary of seventy thousand four hundred dollars and beginning January 1, 1999, the collector of revenue in a city not within a county shall receive an annual salary of seventy-seven thousand four hundred forty dollars. Beginning January 1, 2000, the compensation of the collector of revenue in a city not within a county may be annually increased by an amount equal to the annual salary adjustment for employees of such city as approved by the board of aldermen of such city. Such salary shall be paid out of the city treasury, in equal semimonthly installments, and shall be in lieu of all other amounts otherwise provided by law.