No officer making a sale as prescribed in section 231, or guardian of an infant party, or any person for his benefit, directly or indirectly, shall purchase or be interested in the purchase of any of the property sold; except that a guardian, where he is lawfully authorized to do so, may purchase for the benefit or in behalf of his ward. The violation of this section is a misdemeanor; and a purchase made contrary to this section is void.
N.Y. Real Prop. Acts. Law § 232