The document informs the seller of the amount the buyer is willing to pay and specifies various terms the seller must satisfy if the buyer agrees to the sale. Purchase and Sale Agreement.A purchase and sale agreement is a contract between a buyer and seller for transacting a property in exchange for a specific price. The Purchasing Department has established price contracts and vendor lists to identify suppliers. The Seller agrees to sell and Buyer agrees to buy the following property, located in the Bexar County, State of Texas,. SAWS will convey the SAWS Property to the Successful.