"(a) All sums assessed by the administrator, or the board of administration, or other form of administration specified in the bylaws, but unpaid, for the share of common expenses chargeable to any apartment shall constitute a lien on such apartment prior to all other liens except only (i) tax liens on the apartment in favor of any assessing unit, and (ii) mortgage and other liens, duly recorded, encumbering the apartment. Such lien may be foreclosed by suit by the administrator, or the board of administration, or other form of administration specified in the bylaws, acting on behalf of the council of co-owners, in like manner as a mortgage of real property. In any such foreclosure the apartment owner shall be required to pay a reasonable rental for the apartment after the commencement of the foreclosure action and the plaintiff in such foreclosure shall be entitled to the appointment of a receiver to collect such rents. The administrator, or the board of administration, or other form of administration specified in the bylaws, acting on behalf of the council of co-owners, shall have the power to bid in the apartment at foreclosure sale and to acquire and hold, lease, mortgage and convey the same. Suit to recover a money judgment for unpaid common expenses may be maintainable without instituting foreclosure proceedings."