Marcus & Millichap’s New Jersey office in Elmwood Park completed two transactions worth a combined $2.1 million, according to an announcement Wednesday from the company.The first transaction was the sale of a freestanding U.S. post office, a 4,125 square-foot net leased property at 237 Philadelphia Ave., in Egg Harbor. The office also closed a multitenant retail investment at a 7,100 square-foot property in Hopatcong.