(a) A governing body may use any surplus funds arising from the service charge for the purchase and cancellation of any bonds or other forms of indebtedness issued pursuant to this act. The purchase price of the bonds shall not be either:
(i) Greater than par, plus a premium not to exceed fifty percent (50%) of the face value of all unearned interest coupons attached to any bond purchased; or (ii) More than the actual market price of the bonds or other forms of indebtedness at the time of purchase.