The commissioner of transportation shall not expend money for the acquisition of advertising devices controlled under this chapter, except those for which acquisition proceedings were begun before June 8, 1979, or for which federal money has been appropriated by Congress and the federal share has been made available to the commissioner. No advertising device legal under Laws 1971, chapter 883, shall be required to be removed or relocated until payment as provided in Laws 1971, chapter 883, is tendered by the commissioner of transportation. No further state funds shall be used for any existing or proposed acquisitions other than those funds necessary to obtain full federal participation in the acquisition proceeding pursuant to United States Code, title 23, “Highways.”