Whenever the Governor and the State Treasurer shall be empowered by law to issue general obligation bonds of the State, they may receive bids on more than one issue at the same time and, in such event, may impose as a condition to bidding a requirement that all who shall bid shall submit proposals for all bonds then offered as though such bonds constituted only a single issue of bonds. Under such circumstances, the fact that more than one issue of bonds is offered, and the maturity schedules of the issues are dissimilar, shall be disregarded and the bonds shall be awarded to the bidder whose bid prescribes the lowest interest cost, calculated on the basis that all bonds then issued constituted but a single issue of bonds, rather than more than one issue of bonds.