N.Y.C. Admin. Code § 20-750: § 20-750 Display of service prices.

(a) Every retail service establishment must post, at each counter or desk at which orders are placed and/or payment is made, a list conspicuously displaying the current selling price of the basic services provided. The list shall also disclose factors which may cause the price to be higher than the basic price, and the range of the possible additional charges when such variables pertain.

(b) In the event of a special sale or promotion, the regular price list shall remain conspicuously visible.

c. Notwithstanding any other law, rule or regulation, and in addition to any other penalties provided in this code or elsewhere, the disclosure of differing prices or fees based upon gender by a retail service establishment shall constitute a violation of this subchapter.