§ 35.08 ADDITIONAL PURCHASES AFTER COMPETITIVE BIDDING.
   The purchasing agent may make additional purchases of supplies, materials, equipment or services from a successful bidder, provided that:
   (A)   Amounts of additional purchase are at the same cost or less per quantity as originally bid by the vendor;
   (B)   Amounts of additional purchase do not exceed the cost of the original purchase;
   (C)   The purchase occurs not more than 12 months after the date of the original purchase; and
   (D)   The purchasing agent is reasonably certain that the same supply, material, equipment or service is not available at a lesser cost from any source.