All costs and expenses connected with a plan of conversion shall be paid for or reimbursed by the mutual company or the converted stock company from the proceeds of the offering; provided, that if the plan provides either for a holding company to acquire the stock of the converted stock company or for the merger of the mutual company into a stock insurance company as provided in § 31-906(h), the acquiring holding company or the stock insurance company shall pay for or reimburse all the costs and expenses connected with the plan.