The property and improvements which the Seller is agreeing to sell and which the Purchaser is agreeing to purchase is known as. An attorney's explanation of an Office Purchase and Sales Agreement and its free template for commercial real estate.Representations and Warranties of Seller. 7. A commercial real estate purchase agreement is a legal document between a buyer seeking to purchase commercial property from a seller for an agreed-upon price. Compare handpicked and vetted contract lawyers to save your money and time.