N.J. Stat. Ann. § 40:37B-18

Bonds and notes of an authority may be sold, as hereinafter provided, at public or private sale at such price or prices as the authority shall determine; provided, however, that the interest cost to their average maturity of the money received for any group of bonds sold in a single transaction (computed according to standard tables of bond values) shall not exceed 6% per annum. No obligations shall be sold for less than par value and interest accrued to date of delivery.