Who Bids on the Second Phase?

On some government projects, contractors who win and perform work on the first phase are not permitted to bid on the second phase. This is done so that the contractors bidding on the second phase all start from the same knowledge base. But if the right artifacts are built during the first phase and are made available to potential bidders for the second phase, this negates most of the competitive disadvantage. I believe contractors who perform the first phase well should be permitted to bid on the second phase. This gives them additional incentive to perform. If you allow this, you must also consider what to do if the bid from the first-phase contractor is significantly different (higher or lower) from those of the other bidders. Does that contractor know about risks in the artifacts that are not available to the other contractors? Does that contractor possess knowledge of risks that is unavailable to the other bidders? Be prepared to consider these scenarios.