The Secretary is authorized to make advances from time to time, from the funds provided in section 515f of this title, to the tobacco commission established by the State act of each State which enters into a compact or compacts under the consent given by section 515 of this title in such amounts as the Secretary shall determine to be required for the payment of administrative expenses incurred by such commission, and under such terms and conditions with respect to the expenditure thereof as the Secretary shall stipulate: Provided, That each State act creating such commission shall provide for the repayment to the Secretary of such advances from any funds received by the commission from the sale of marketing certificates with respect to tobacco, prior to the use of such funds for any other purpose