All goods and services purchased under the provisions of this article must be competitively bid or procured as provided for in this article. However, goods and services may be purchased from vendors that have been awarded a current and valid GSA contract. Prices paid for such goods and services may not exceed the lowest competitively bid price for these goods or services. In contracting for the purchase of utilities, the Director of Finance may not purchase services if the price exceeds the price in an existing state contract. The Director of Finance may require any additional terms and conditions determined to be necessary.