The Tax Court is authorized to make such expenditures (including expenditures for personal services and rent at the seat of Government and elsewhere, and for law books, books of reference, and periodicals), as may be necessary efficiently to execute the functions vested in the Tax Court. Notwithstanding any other provision of law, the Tax Court is authorized to pay on behalf of its judges, age 65 or over, any increase in the cost of Federal Employees’ Group Life Insurance imposed after