The Mississippi Agricultural and Industrial Board is authorized and empowered to contract and pay for the services set out in the foregoing section, in such amount or amounts as may be necessary to attain the objectives of Sections 57-11-31 through 57-11-39, provided such commitments and expenditures are not to exceed the sum of one hundred fifty thousand dollars ($150,000.00) appropriated by the Mississippi Legislature for special market research and do not, at any time, exceed for plant design and engineering the amount or balance that may be available in a special "plant engineering revolving fund" maintained in the state treasury by an initial appropriation by the Mississippi Legislature in the amount of two hundred fifty thousand dollars ($250,000.00).