The effectuation of the authorized purposes of authorities created under this subdivision shall and will be in all respects for the benefit of the people of this Commonwealth, for the increase of their commerce and prosperity and for the improvement of their health and living conditions; and since authorities, as public instrumentalities of the Commonwealth, will be performing essential governmental functions in effectuating these purposes, the authorities shall not be required to pay any taxes or assessments upon a convention center facility, or parts thereof, or property acquired or used or permitted to be used by them for these purposes; and the bonds issued by any authority, their transfer and the income from the bonds, including any profits made on the sale of the bonds, shall at all times be free from State and local taxation within this Commonwealth. This exemption shall not extend to gift, estate, succession or inheritance taxes or any other taxes not levied directly on the bonds, their transfer or the income from or the realization of profits on the sale of the bonds.