N.J. Stat. Ann. § 17:3B-24

Collection costs in a closed end credit arrangement. Upon the filing of an action for the collection of an amount in default under the terms of the loan agreement, the lender, in addition to the recovery of all court costs, reasonable attorney's fees and expenses of repossession and storing goods where so authorized by law, may charge and collect from the borrower other reasonable collection costs incurred, not to exceed 20% of the first $500.00 of the unpaid balance of the loan, 10% of the amount over $500.00 up to $2,000.00, and 5% of any amount in excess of $2,000.00.