You are familiar with the three reasons for the initial market research: becoming an informed consumer, locating small business solutions, and locating a commercial item solution.  You are correct, market research should be performed as necessary.  Now step back and use your knowledge of the scope of the IDIQ and the contractors. You are not re-inventing the IDIQ but only validating the requirements and the vendor's capability.  You will need to validate through all available market sources that both the requirements are still valid and that the firms are still capable of performing..